--------------------------------------------------------------------------------
MODULE TRIGRID
--------------------------------------------------------------------------------
REPLACES PANACEA module PANDORA.
--------------------------------------------------------------------------------
TRIGRID takes the triangulation node and data files created by TRIANG (or edited output from TRIEDIT) and the slope derivative file generated by TRIDER, and produces a DTI (Digital Terrain Image) output file containing a regular grid DTM.
$ TRIGRID
None, TRIGRID is command driven.
--------------------------------------------------------------------------------
TRIGRID takes the triangulation node and data files created by TRIANG (or edited output from TRIEDIT) and the slope derivative file generated by TRIDER, and produces a DTI (Digital Terrain Image) output file containing a regular grid DTM.
Once the triangulation and derivative input files are available, TRIGRID may be used repeatedly to produce DTM grids from the same triangulation area at differing resolutions.
TRIGRID offers 2 types of interpolation from the triangular form to the DTM grid.
The smooth patch option is enabled by default.
The advantage of using the linear FACET approach is that it is faster and will definitely produce no values outside the z-range of the data set. If a surface is well defined by contours and spot heights or a quick "look-see" model is required then the FACET option is strongly recommended.
The SMOOTH patch option is the most complicated as it generates a fully edge continuous interpolation across the triangulated area. The smooth patch option uses a quintic surface patch fitted to the vertices and estimated derivatives of the triangles to interpolate a grid node location falling within the triangle. The option should be used with caution, as in areas of very sparse data points the results are those of a mathematical patch, NOT necessarily those of a physical environment function! There are however modifying triangle limits (see Commands section) which may be applied in association with the smooth patch option, which can be used to prevent undershoot and overshoot outside a specified z-range. There are no triangle limits to be set up for the linear FACET option.
The size of the DTM generated by TRIGRID is controlled by either:
For the simplest possible gridding run TRIGRID requires that the following obligatory commands are given:
1) WINDOW 2) SIZE (or SIDELENGTH) 3) FILEIN 4) FILEOUT 5) GO
WINDOW 'xmin' 'ymin' 'xmax' 'ymax' - determines the geographical extent of the DTM to be gridded, for example:
WINDOW 40.0 20.0 100.0 100.0
defines the area of the DTM as lying between forty and one hundred units in X and twenty and one hundred units in Y. Data in the triangulation files which lie outside the specified area will be ignored.
The specified extent need not cover the whole area contained in the structured data files. It is possible to "window" out sub-areas of DTM and patch them together to form a complete model using the MATRIX DTITILE utility at a later date.
EITHER:
SIZE 'ncols' 'nrows' - enables the user to explicitly force the model size
to be ncol columns and nrow rows. This an alternative to the
SIDELENGTH command.
OR:
SIDELENGTH 'x_step' 'y_step' - enables the user to explicitly set the sidelength in X and Y for the individual DTM cells. Using SIDELENGTH the number of rows and columns is calculated for you.
Failure to define the grid WINDOW will result in the message:
You must set the grid SIDELENGTH (or use SIZE) and WINDOW before
gridding can begin.
when you attempt to issue a GO command.
When you use SIZE the minimum possible number of rows and columns
is 3. If you try to specify less than this the message:
You must have at least 3 rows and 3 columns in your DTM
will appear.
Failure to specify a size for both rows and columns will
result in TRIGRID assuming that you wish both sides to be equal and
the message:
Number of columns and rows assumed equal ( 'integer' 'integer' )
will appear.
If you have already issued a SIDELENGTH command then the sidelength
values that you specified will be replaced by the values calculated from
WINDOW divided by the number of rows and number of columns and the message:
Over-riding SIDELENGTH settings
will appear.
If you have already specified values for the WINDOW then TRIGRID
will calculate the cell sidelength required to give you the the
number of rows and columns specified by the SIZE command and the
results of this calculation will be displayed:
Window units are metres Triangulation coverage SW: 'real' 'real' NE: 'real' 'real' Triangulation window SW: 'real' 'real' NE: 'real' 'real' Which with a side length of 10.00 in X and 10.00 in Y gives 'integer' rows and 'integer' columns in the dtm
You may use the SIDELENGTH, SIZE and WINDOW commands in combination as often as you wish until the desired model characteristics are achieved.
FILEIN 'file-spec' - This command causes the specified triangulation files (_.NOD, _.DTA and _.DER) to be read as input.
FILEOUT 'file-spec' - create this DTI file for output.
GO - start processing.
--------------------------------------------------------------------------------
A typical command sequence is:
TRIGRID> WINDOW 0.0 0.0 80.0 160.0! determine area of DTM TRIGRID> SIDELENGTH 10.0 12.0 ! cell sidelength in X and in Y TRIGRID> ZLIMITS 0.0 456.0 ! overall DTM interpolation limits TRIGRID> TRIANGLE_LIMITS 3.0 9.0 ! individual triangle interpolation limits TRIGRID> FILEIN FRED ! read in FRED_.DTA, FRED_.NOD, and FRED_.DER TRIGRID> ENABLE TRACE ! trace along original data strings for TRIGRID> ! up-hill/down-hill side of line information TRIGRID> DATA_TYPE REAL ! output DTM posts as real (floating point) TRIGRID> FILEOUT TEST3.DTI ! create DTI file LSL$DTI:TEST3.DTI a TRIGRID> ! the output file TRIGRID> GO ! go!
----------------------------------------------------------------------
TRIGRID expects as input the binary structured data files (the matched pair of _.NOD and _.DTA files) produced by TRIANG or TRIEDIT. It also needs the slope derivative (_.DER) file produced by TRIDER. All three files must share the same generic filename and must have the same version number. The single TRIGRID FILEIN command supplies a file-spec which is used as a generic file-spec for all three input (_.NOD, _.DTA and _.DER) files.
Any parts missing from the generic file-specification are taken from the defaults SYS$DISK:[]_.DTA;0 and SYS$DISK:[]_.NOD;0.
Since it is essential that the file version numbers of the _.NOD, _.DTA and _.DER file always match, TRIGRID performs checks on file version numbers. If mismatches are found, TRIGRID complains and aborts execution.
Never use the VAX/VMS RENAME or COPY commands to alter the version numbers of _.NOD, _.DTA files or _.DER files to make them into a matched set. TRIDER will have to be re-run every time that the _.NOD and _.DTA files are modified using TRIEDIT.
The output files from TRIANG, TRIEDIT and TRIDER will be scaled to lie between 0 and the value defined by logical, LSL$DTMCREATE_RESOLUTION, or 300000 if the logical is not defined. The valid range for this resolution is between 300000 and 10000000.
TRIGRID uses this logical value to determine the internal resolution of the _.NOD, _.DTA and _.DER files.
TRIGRID generates output files in DTI (Digital Terrain Image) format, (for a description of DTI format see the MATRIX Reference Manual). TRIGRID offers the choice of output of 3 DTI data types:
These may be set using the DATA_TYPE command.
By default a DTI file of data type WORD is generated.
TRIGRID also offers the user a choice of 3 DTI header types:
By default the DTI file is given the LSLA type header.
If a set type 2 IFF MD (Map Descriptor) or a set DTI file projection record were available in the first file read into TRIANG using a FILEIN command, TRIANG puts this information into the _.NOD and _.DTA files. If TRIGRID is creating a DTI file with an LSLA type header this projection information is copied from the _.DTA amd _.NOD files into the TRIGRID DTI file header after appropriate modifications of extent, origin and gridstep.
The output DTI file header type may be set using the HEADER_TYPE command.
For details of the characteristics of the different DTI file header types see the Matrix Reference Manual. For information about which of the header characteristics are set by TRIGRID see the HEADER_TYPE command below.
--------------------------------------------------------------------------------
TRIGRID offers the user graphics output of the type offered by TRIANG and TRIDER. The convoluted process of grid height estimation may be observed! The graphics option is a useful aid for instruction or for the analysis of troublesome data sets.
--------------------------------------------------------------------------------
_@
Take command input from the specified file.
--------------------------------------------------------------------------------
FORMAT: _@file-spec<CR>
--------------------------------------------------------------------------------
Command parameters:
file-spec
The file to be opened and used for command input.
Any parts of the file-spec not supplied for the @ command will be taken from the default specification 'SYS$DISK:[].COM;0'.
--------------------------------------------------------------------------------
DESCRIPTION:
TRIGRID offers the facility of command input from an indirect command file. The '@' character preceding a file-spec will cause TRIGRID to open and read commands from the specified file until:
Nested command files are not supported (i.e. a command file containing an '@' command), although sequential '@' commands are supported when read from SYS$COMMAND.
As an aid to batch log interpretation TRIGRID will echo all commands read from an indirect command file.
--------------------------------------------------------------------------------
Messages:
The following messages are specific to the _@ command:
*** WARNING *** "@" must precede a file-spec
*** WARNING *** Indirect file error - returning to terminal input
*** ERROR *** Can't open indirect command file 'file-spec'
--------------------------------------------------------------------------------
Examples:
$ TRIGRID<CR>
DTMCREATE module TRIGRID of 16:30:12 20-NOV-87
TRIGRID> @FLOW2<CR>
TRIGRID> ENABLE DIAGNOSTICS
TRIGRID> ENABLE GRAPHICS
TRIGRID> RETURN
TRIGRID>
--------------------------------------------------------------------------------
_!
Treat all text to the right of the '!' as a comment.
--------------------------------------------------------------------------------
FORMAT: _! [comment text]
--------------------------------------------------------------------------------
Command parameters:
comment text
text that is to be treated as a comment and which will be excluded from command interpretation.
--------------------------------------------------------------------------------
DESCRIPTION:
An exclamation mark is the standard DTMCREATE package comment delimiter. All text (and numbers) which lie to the right of a '!' character are excluded from command interpretation. Comments are useful for annotating command procedures used in batch processing etc_.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
TRIGRID> _! a comment for the sake of it<CR>
TRIGRID> ENABLE GRAPHICS ! turn graphics on<CR>
TRIGRID>
--------------------------------------------------------------------------------
DATA_TYPE
The DATA_TYPE command specifies the data type of the posts in the output DTI file.
--------------------------------------------------------------------------------
FORMAT: DATA_TYPE type
--------------------------------------------------------------------------------
Command parameters:
type
A data type keyword chosen from:
--------------------------------------------------------------------------------
DESCRIPTION:
The DATA_TYPE allows the user to specify the data type of the output DTI file which contains the DTM grid.
By default TRIGRID generates a 'MIKE' type DTI file having WORD (16 bit integer) post values.
When choosing the data type of the DTI file, consideration must be given to the Z range of the data to be output. TRIEDIT will output the DTMCREATE default null value (-32767) if data underflow or overflow occurs when writing to the DTI file.
Consideration must also be given to the nature of the output DTM. Remember that integer DTI data types (WORD and LONGWORD) quantise the Z data values. By default Z values are truncated to the next lower integer value. If the NINT option is enabled, Z values in integer DTI files are rounded to the nearest whole integer.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
TRIGRID> DATA_TYPE REAL<CR>
TRIGRID> SHOW DATA_TYPE<CR>
DTI data type ....................................... REAL
TRIGRID>
--------------------------------------------------------------------------------
DISABLE AUTO_LIMITS
Disables a previous ENABLE AUTO_LIMITS command.
--------------------------------------------------------------------------------
FORMAT: DISABLE AUTO_LIMITS
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
DISABLE AUTO_LIMITS allows the user to cancel the effect of a previous ENABLE AUTO_LIMITS command.
When the AUTO_LIMITS option is active, TRIGRID applies interpolation limits based on the feature flag information attached to each node in the triangulation. It is then impossible, for example, for a grid height to be set below the height of a triangle vertex that is flagged as being part of a river string.
By default, the AUTO_LIMITS option is enabled during program startup.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
TRIGRID> ENABLE AUTO_LIMITS<CR>
TRIGRID> SHOW ENABLE<CR>
AUTO_LIMITS ......................................... On
DIAGNOSTICS ......................................... Off
GRAPHICS ............................................ Off
SMOOTH .............................................. On
(Smooth patch interpolation)
NINT ................................................ On
ORTHOGONAL .......................................... Off
TRACE ............................................... Off
TRIGRID>
--------------------------------------------------------------------------------
DISABLE DEBUG
Disables a previous ENABLE DEBUG command.
--------------------------------------------------------------------------------
FORMAT: DISABLE DEBUG
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
DISABLE DEBUG allows the user to cancel the effect of a previous ENABLE DEBUG command.
When the DEBUG option is active, TRIGRID produces copious debugging information. The DEBUG option is reserved for use by Laser-Scan personnel.
By default, the DEBUG option is disabled during program startup.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
TRIGRID> ENABLE DEBUG<CR>
TRIGRID>
--------------------------------------------------------------------------------
DISABLE DIAGNOSTICS
Disables a previous ENABLE DIAGNOSTICS command.
--------------------------------------------------------------------------------
FORMAT: DISABLE DIAGNOSTICS
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
DISABLE DIAGNOSTICS allows the user to cancel the effect of a previous ENABLE DIAGNOSTICS command.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
TRIGRID> ENABLE DIAGNOSTICS<CR>
TRIGRID> SHOW ENABLE<CR>
AUTO_LIMITS ......................................... On
DIAGNOSTICS ......................................... On
GRAPHICS ............................................ Off
SMOOTH .............................................. On
(Smooth patch interpolation)
NINT ................................................ On
ORTHOGONAL .......................................... Off
TRACE ............................................... Off
TRIGRID>
--------------------------------------------------------------------------------
DISABLE GRAPHICS
Disables any previous ENABLE GRAPHICS command.
--------------------------------------------------------------------------------
FORMAT: DISABLE GRAPHICS
--------------------------------------------------------------------------------
Command parameter: None.
--------------------------------------------------------------------------------
DESCRIPTION:
The DISABLE GRAPHICS command cancels the effect of a previous ENABLE GRAPHICS command.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
--------------------------------------------------------------------------------
DISABLE NINT
Disables a previous ENABLE NINT command.
--------------------------------------------------------------------------------
FORMAT: DISABLE NINT
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
DISABLE NINT allows the user to cancel the effect of a previous ENABLE NINT command.
When output is directed to a word or longword DTI file it is necessary to convert the real height value interpolated within TRIGRID to an integer value. This conversion is normally done using the FORTRAN NINT intrinsic function (round to nearest integer). However, some customers prefer to use integer truncation (FORTRAN INT intrinsic function).
The ENABLE NINT and DISABLE NINT commands allow the user to specify which of these two functions is to be used, i.e.
ENABLE NINT - use NINT, round to nearest integer value (Default) DISABLE NINT - use INT, truncate to integer value
By default, the NINT option is enabled during program startup.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
TRIGRID> ENABLE NINT<CR>
TRIGRID> SHOW ENABLE<CR>
AUTO_LIMITS ......................................... On
DIAGNOSTICS ......................................... Off
GRAPHICS ............................................ Off
SMOOTH .............................................. On
(Smooth patch interpolation)
NINT ................................................ On
ORTHOGONAL .......................................... Off
TRACE ............................................... Off
TRIGRID>
--------------------------------------------------------------------------------
DISABLE ORTHOGONAL
Disables a previous ENABLE ORTHOGONAL command.
--------------------------------------------------------------------------------
FORMAT: DISABLE ORTHOGONAL
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
DISABLE ORTHOGONAL allows the user to cancel the effect of a previous ENABLE ORTHOGONAL command.
When the ORTHOGONAL option is active, individual triangle interpolation under-shoot and over-shoot limits are applied orthogonal to the triangle facet plane. The default action is to apply the limits vertically regardless of the slope of the triangle facet plane. ENABLE ORTHOGONAL is not recommended for use with data sets which have regularly spaced contours of regular interval but will be beneficial if the contour data have an irregular interval and have irregular spacing.
By default, the ORTHOGONAL option is disabled during program startup.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
--------------------------------------------------------------------------------
DISABLE PME
DISABLE PME disables the effect of a previous ENABLE PME command.
--------------------------------------------------------------------------------
FORMAT: DISABLE PME
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
The ENABLE PME and DISABLE PME commands are reserved for Laser-Scan use. PME is a code optimisation tool and should be invoked by LSL software personnel only.
DISABLE PME disables the effect of a previous ENABLE PME command and causes the PME_EXIT routine to be invoked.
--------------------------------------------------------------------------------
Message:
The following warning message is specific to the DISABLE PME command:
*** WARNING *** You were not using PME anyway!
--------------------------------------------------------------------------------
Examples:
$ TRIGRID<CR>
DTMCREATE module TRIGRID of 13:30:39 20-AUG-87
TRIGRID> ENABLE PME ! turn PME on<CR>
TRIGRID> DISABLE PME ! turn it off again!!<CR>
TRIGRID>
--------------------------------------------------------------------------------
DISABLE SMOOTH
Disables a previous ENABLE SMOOTH command.
--------------------------------------------------------------------------------
FORMAT: DISABLE SMOOTH
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
DISABLE SMOOTH allows the user to cancel the effect of a previous ENABLE SMOOTH command.
By default, the SMOOTH option is enabled during program startup.
The DISABLE SMOOTH command disables grid point estimation by smooth patches. Grid heights are instead estimated using linear interpolation across the triangle facet planes. Smooth patch estimation tends to give a more rounded smooth appearance to a DTM surface than that given by linear facets.
If smooth patch interpolation is selected, individual triangle interpolation limits are applied. Linear facet interpolation, by definition, does not need to apply interpolation limits as interpolation is restricted to the triangle facet plane.
For further details of interpolation limits, see the LIMITS, TRIANGLE_LIMITS and ENABLE AUTO_LIMITS commands.
--------------------------------------------------------------------------------
Messages:
The following messages are specific to the DISABLE SMOOTH command:
*** WARNING *** Linear facet interpolation selected. No smooth patch interpolation limits will be applied and the ENABLE TRACE command will be ignored *** WARNING *** Linear facet interpolation selected. The ENABLE TRACE command and any smooth patch interpolation will be ignored
--------------------------------------------------------------------------------
Examples:
TRIGRID> DISABLE SMOOTH<CR>
*** WARNING *** Linear facet interpolation selected. The ENABLE TRACE command and any smooth patch interpolation will be ignored
--------------------------------------------------------------------------------
DISABLE TRACE
Disables a previous ENABLE TRACE command.
--------------------------------------------------------------------------------
FORMAT: DISABLE TRACE
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
DISABLE TRACE allows the user to cancel the effect of a previous ENABLE TRACE command.
The TRACE option causes TRIGRID to calculate up-hill/down-hill side of line context for the original data strings input to (and optionally constrained) in TRIANG. These up-hill/down-hill data are then used to apply further interpolation limits to each individual triangle. These additional limits ensure that triangles whose vertices indicate a flat plane do bulge in the correct direction relative to surrounding hill slopes even when the slope derivatives estimated for the triangle vertices conflict due to complex surrounding relief.
It is strongly recommended that the trace option is selected, particularly if the resulting DTM is to be re-contoured.
By default, the TRACE option is disabled during program startup.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
TRIGRID> ENABLE TRACE<CR>
TRIGRID> SHOW ENABLE<CR>
AUTO_LIMITS ......................................... On
DIAGNOSTICS ......................................... Off
GRAPHICS ............................................ Off
SMOOTH .............................................. On
(Smooth patch interpolation)
NINT ................................................ On
ORTHOGONAL .......................................... Off
TRACE ............................................... Off
TRIGRID>
--------------------------------------------------------------------------------
ENABLE AUTO_LIMITS
Enables the application of automatic limits to grid interpolation.
--------------------------------------------------------------------------------
FORMAT: ENABLE AUTO_LIMITS
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
ENABLE AUTO_LIMITS enables the user to activate the application of automatic limits to grid interpolation.
When the AUTO_LIMITS option is active, TRIGRID applies interpolation limits based on the feature flag information attached to each node in the triangulation. It is then impossible, for example, for a grid height to be set below the height of a triangle vertex that is flagged as being part of a river string.
By default, the AUTO_LIMITS option is enabled during program startup.
The AUTO_LIMITS option may be cancelled by the DISABLE AUTO_LIMITS command.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
TRIGRID> ENABLE AUTO_LIMITS<CR>
TRIGRID>
--------------------------------------------------------------------------------
ENABLE DEBUG
Enables output of debug information. The ENABLE DEBUG command is reserved for use by Laser-Scan personnel.
--------------------------------------------------------------------------------
FORMAT: ENABLE DEBUG
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
When the DEBUG option is active, TRIGRID produces copious debugging information. The DEBUG option is reserved for use by Laser-Scan personnel.
By default, the DEBUG option is disabled during program startup.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
TRIGRID> ENABLE DEBUG<CR>
TRIGRID>
--------------------------------------------------------------------------------
ENABLE DIAGNOSTICS
ENABLE DIAGNOSTICS allows the user to enable diagnostic printout.
--------------------------------------------------------------------------------
FORMAT: ENABLE DIAGNOSTICS
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
ENABLE DIAGNOSTICS allows the user to enable diagnostic printout.
Because it is usually used in a batch processing environment, by default TRIGRID produces minimal diagnostic printout. If however, the user wishes to receive indications of processing progress and of the effect of selections on data input, diagnostic printout may be selected with the ENABLE DIAGNOSTICS command.
On a heavily loaded computer it may be reassuring to ENABLE DIAGNOSTICS to indicate progress through the data set. If SYS$OUTPUT is directed to a video screen terminal, messages indicating percentage progress are issued.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
TRIGRID> ENABLE DIAGNOSTICS<CR>
TRIGRID> SHOW ENABLE<CR>
AUTO_LIMITS ......................................... On
DIAGNOSTICS ......................................... On
GRAPHICS ............................................ Off
SMOOTH .............................................. On
(Smooth patch interpolation)
NINT ................................................ On
ORTHOGONAL .......................................... Off
TRACE ............................................... Off
TRIGRID>
--------------------------------------------------------------------------------
ENABLE GRAPHICS
Enable TRIGRID graphics output.
--------------------------------------------------------------------------------
FORMAT: ENABLE GRAPHICS
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
TRIGRID offers the option to generate graphic output to indicate processing progress. By default graphic output is disabled. To prevent a user selecting graphics when it is inappropriate to the current terminal, TRIGRID uses a lookup table of terminal characteristics associated with all available terminal lines (see Appendix 1). An invalid graphics selection will result in a warning message and the GRAPHICS option being deselected.
Graphics selection may be cancelled with the DISABLE GRAPHICS command.
--------------------------------------------------------------------------------
Messages:
The following messages are specific to the ENABLE GRAPHICS command:
*** ERROR *** reading lookup file at line 'integer' *** WARNING *** Unable to open "LSL$LOOKUP:TERMTYPE.DAT" Sorry 'name' terminal 'terminal-ident' isn't in the lookup table Sorry 'name' terminal 'terminal-ident' can't support graphics *** ERROR *** translating logical name LSL$DTMCREATETERMINAL
--------------------------------------------------------------------------------
Examples:
$ TRIGRID<CR>
DTMCREATE module TRIGRID of 13:30:39 20-AUG-87
TRIGRID> ENABLE GRAPHICS<CR>
TRIGRID>
--------------------------------------------------------------------------------
ENABLE NINT
Enable rounding of grid z-values to the nearest integer, i_.e_. used for word and longword DTI data types.
--------------------------------------------------------------------------------
FORMAT: ENABLE NINT
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
When output is directed to a word or longword DTI file it is necessary to convert the real height value interpolated within TRIGRID to an integer value. This conversion is normally done using the FORTRAN NINT intrinsic function (round to nearest integer). However, some customers prefer to use integer truncation (FORTRAN INT intrinsic function).
The ENABLE NINT and DISABLE NINT commands allow the user to specify which of these two functions is to be used, i.e.
ENABLE NINT - use NINT, round to nearest integer value (Default) DISABLE NINT - use INT, truncate to integer value
By default, the NINT option is enabled during program startup.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
TRIGRID> ENABLE NINT<CR>
TRIGRID> SHOW ENABLE<CR>
AUTO_LIMITS ......................................... On
DIAGNOSTICS ......................................... Off
GRAPHICS ............................................ Off
SMOOTH .............................................. On
(Smooth patch interpolation)
NINT ................................................ On
ORTHOGONAL .......................................... Off
TRACE ............................................... Off
TRIGRID>
--------------------------------------------------------------------------------
ENABLE ORTHOGONAL
Causes individual triangle interpolation under-shoot and over-shoot limits to be applied orthogonal to the triangle facet plane.
--------------------------------------------------------------------------------
FORMAT: ENABLE ORTHOGONAL
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
When the ORTHOGONAL option is active, individual triangle interpolation under-shoot and over-shoot limits are applied orthogonal to the triangle facet plane. The default action is to apply the limits vertically regardless of the slope of the triangle facet plane. ENABLE ORTHOGONAL is not recommended for use with data sets which have regularly spaced contours of regular interval but will be beneficial if the contour data have an irregular interval and have irregular spacing.
The effect of an ENABLE ORTHOGONAL command may be cancelled with a DISABLE ORTHOGONAL command.
By default, the ORTHOGONAL option is disabled during program startup.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
TRIGRID> ENABLE ORTHOGONAL<CR>
TRIGRID> SHOW ENABLE<CR>
AUTO_LIMITS ......................................... On
DIAGNOSTICS ......................................... Off
GRAPHICS ............................................ Off
SMOOTH .............................................. On
(Smooth patch interpolation)
NINT ................................................ On
ORTHOGONAL .......................................... On
TRACE ............................................... Off
TRIGRID>
--------------------------------------------------------------------------------
ENABLE PME
ENABLE PME enables the PME performance monitor.
--------------------------------------------------------------------------------
FORMAT: ENABLE PME
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
The ENABLE PME and DISABLE PME commands are reserved for Laser-Scan use. PME is a code optimisation tool and should be invoked by LSL software personnel only.
ENABLE PME causes the PME_INIT routine to be invoked.
--------------------------------------------------------------------------------
Message:
The following warning message is specific to the ENABLE PME command:
*** WARNING *** You are already using PME!
--------------------------------------------------------------------------------
Examples:
$ TRIGRID<CR>
DTMCREATE module TRIGRID of 13:30:39 20-AUG-87
TRIGRID> ENABLE PME<CR>
TRIGRID> FILEIN DUA3:[DEMONSTRATION]IDAHO<CR>
_.DTA file DUA3:[DEMONSTRATION]IDAHO_.DTA;15 opened for read
_.NOD file DUA3:[DEMONSTRATION]IDAHO_.NOD;15 opened for read
_.DER file DUA3:[DEMONSTRATION]IDAHO_.DER;15 opened for read
TRIGRID>
--------------------------------------------------------------------------------
ENABLE SMOOTH
Enables grid point estimation by smooth patches.
--------------------------------------------------------------------------------
FORMAT: ENABLE SMOOTH
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
The ENABLE SMOOTH command enables grid point estimation by smooth patches. Smooth patch estimation tends to give a more rounded smooth appearance to a DTM surface than that given by linear facets.
By default, the SMOOTH option is enabled during program startup.
If smooth patch interpolation is selected, individual triangle interpolation limits are applied. Linear facet interpolation, by definition, does not need to apply interpolation limits as interpolation is restricted to the triangle facet plane.
The DISABLE SMOOTH command disables grid point estimation by smooth patches. Grid heights are instead estimated using linear interpolation across the triangle facet planes.
For further details of interpolation limits, see the LIMITS, TRIANGLE_LIMITS and ENABLE AUTO_LIMITS commands.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
TRIGRID> ENABLE SMOOTH<CR>
TRIGRID>
--------------------------------------------------------------------------------
ENABLE TRACE
Causes calculation of up-hill/down-hill side of line context for the original data strings input to (and optionally constrained) in TRIANG or modified in TRIEDIT.
--------------------------------------------------------------------------------
FORMAT: ENABLE TRACE
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
The TRACE option causes TRIGRID to calculate up-hill/down-hill side of line context for the original data strings input to (and optionally constrained) in TRIANG. These up-hill/down-hill data are then used to apply further interpolation limits to each individual triangle. These additional limits ensure that triangles whose vertices indicate a flat plane do bulge in the correct direction relative to surrounding hill slopes even when the slope derivatives estimated for the triangle vertices conflict due to complex surrounding relief.
It is strongly recommended that the trace option is selected, particularly if the resulting DTM is to be re-contoured.
By default, the TRACE option is disabled during program startup.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
TRIGRID> ENABLE TRACE<CR>
TRIGRID>
--------------------------------------------------------------------------------
FILEIN
Specifies the generic (_.DTA, _.NOD and _.DER) file-spec that is to be used for input.
--------------------------------------------------------------------------------
FORMAT: FILEIN file-spec
--------------------------------------------------------------------------------
COMMAND PARAMETERS:
file-spec
The generic specification of the _.NOD _.DTA and _.DER files to be opened for data input.
All components of the supplied file-spec are used to form the input file specifications but with the substitution of the extensions _.NOD, _.DTA and _.DER and version number ';0', i.e. latest version (shared by all three files).
The default file-spec used to make up missing parts of the FILEIN file-spec parameter is dependent on the status of logical name LSL$DTMCREATE_WORK.
If logical name LSL$DTMCREATE_WORK is defined, DTMCREATE utilities translate the logical name to get the default file-spec for input and output of triangulation files. The logical name should be defined to provide a device and directory name only. The DTMCREATE programs themselves provide the default filename and extension fields of the specification. For example, a valid definition of logical name LSL$DTMCREATE_WORK is:
_$ DEFINE LSL$DTMCREATE_WORK LSL$DATA_ROOT:[LSL.DTMCREATE]
This mechanism allows all DTMCREATE triangulation files to be stored in a central directory, rather than scattered in many different user directories. It thus mimics the use of logical names LSL$IF for IFF files and LSL$DTI for DTI files.
If the logical name is not defined, any parts of the file-spec not supplied for the FILEIN command will be taken from the defaults 'SYS$DISK:[]_.NOD;0' 'SYS$DISK:[]_.DTA;0' and 'SYS$DISK:[]_.DER;0'. These defaults result in the files being searched for in your current default directory, set using the VMS SET DEFAULT or Laser-Scan SD commands.
--------------------------------------------------------------------------------
DESCRIPTION:
TRIGRID expects as input the 2 binary structured data files (the matched pair of _.NOD and _.DTA files) produced by TRIANG or TRIEDIT, and the _.DER file containing the slope derivatives estimated by TRIDER.
The TRIGRID input file specification is used as a generic file-spec for all three input (_.NOD, _.DTA and _.DER) files.
Any parts missing from the generic file-specification are taken from the from the defaults SYS$DISK:[]_.DTA;0 and SYS$DISK:[]_.NOD;0.
Since it is essential that the file version numbers of the _.NOD, _.DTA and _.DER file always match, TRIGRID performs checks on file version numbers. If mismatches are found, TRIGRID complains and aborts execution.
--------------------------------------------------------------------------------
Messages:
The following messages are specific to the FILEIN command:
*** WARNING *** You must specify a file-spec argument to the FILEIN command
For example FILEIN SWAREA_.DTA
*** ERROR *** Unable to interpret input file-spec
*** ERROR *** opening input file
_.DTA file 'file-spec' opened for read
_.NOD file 'file-spec' opened for read
_.DER file 'file-spec' opened for read
--------------------------------------------------------------------------------
Examples:
TRIGRID> FILEIN DUA3:[DEMONSTRATION]IDAHO<CR>
_.DTA file DUA3:[DEMONSTRATION]IDAHO_.DTA;15 opened for read
_.NOD file DUA3:[DEMONSTRATION]IDAHO_.NOD;15 opened for read
_.DER file DUA3:[DEMONSTRATION]IDAHO_.DER;15 opened for read
TRIGRID>
--------------------------------------------------------------------------------
FILEOUT
Specifies the name of the DTI file to be created and opened for output.
--------------------------------------------------------------------------------
FORMAT: FILEOUT file-spec
--------------------------------------------------------------------------------
COMMAND PARAMETERS:
file-spec
The specification of the DTI file to be created and opened for output.
Any parts missing from the file-specification are taken from the default LSL$DTI:DTI.DTI;0.
--------------------------------------------------------------------------------
DESCRIPTION:
The FILEOUT command is used to specify the DTI file which is to be created and opened for data output.
The DTI file is not actually created and opened until a GO command is accepted, as the user may redefine the DTI header type (HEADER_TYPE command) or the DTI data type (DATA_TYPE command) after issuing the FILEOUT command.
By default TRIGRID creates a DTI file having an LSLA type header and word data type.
The characteristics of the output DTI file are determined by the HEADER_TYPE and DATA_TYPE commands, and its size by combinations of WINDOW, SIZE or SIDELENGTH commands.
If a set type 2 IFF MD (Map Descriptor) or a set DTI file projection record were available in the first file read into TRIANG using a FILEIN command, TRIANG puts this information into the _.NOD and _.DTA files. If TRIGRID is creating a DTI file with an LSLA type header this projection information is copied from the _.DTA amd _.NOD files into the TRIGRID DTI file header after appropriate modifications of extent, origin and gridstep.
In contrast, it is left to the user to set DTED DTI file header contents using DTEDIFF and MCEHED.
--------------------------------------------------------------------------------
Messages:
The following messages are specific to the FILEOUT command:
*** WARNING *** You must specify a file-spec argument to the FILEOUT command
For example FILEOUT SWAREA_.DTI
*** ERROR *** Unable to interpret input file-spec
--------------------------------------------------------------------------------
Examples:
TRIGRID> FILEOUT IDAHO<CR>
TRIGRID>
--------------------------------------------------------------------------------
GO
Initiates the processing of the data read in using the FILEIN command.
--------------------------------------------------------------------------------
FORMAT: GO
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
When all necessary files have been read in the GO command will cause the DTI file specified with the FILEOUT command to be created and opened. TRIGRID will then commence the gridding process. Unless relatively small data-sets are being handled (say less then 50,000 data points) it is strongly recommended that TRIGRID is run in batch mode at an off-peak time.
When grid creation is complete, TRIGRID closes the output DTI file and then exits.
Before the GO command will be accepted, TRIGRID performs checks that the following obligatory commands have been issued:
1) WINDOW 2) SIZE (or SIDELENGTH) 3) FILEIN 4) FILEOUT
If one (or more) of these commands has not yet been issued and accepted, TRIGRID will ignore the GO command and prompt for further commands at the terminal. The SHOW ENABLE command can be used to discover the current command option settings.
--------------------------------------------------------------------------------
Messages:
*** WARNING *** The following commands must be given before processing can begin: 1) WINDOW 2) SIZE (or SIDELENGTH) 3) FILEIN 4) FILEOUT
Once the GO command has been accepted no more conversational messages of the *** WARNING *** format will be issued. Any messages will relate to serious processing problems and will normally result in abnormal TRIGRID termination. The messages relating to non-interactive processing problems are presented at the end of this document.
--------------------------------------------------------------------------------
Examples:
TRIGRID> GO<CR>
DTI file LSL$DTI:TEST_DTM.DTI opened for write
File : LSL$DTI:TEST_DTM.DTI
Header : LSLA Data: WORD
Units are Metres
Matrix Coverage SW: 0.00 0.00 NE: 200.00 199.50
Matrix Interval E: 2.00 N: 1.50
Value Range : 0 to 0
ELAPSED: 0 00:05:21.82 CPU: 0:00:01.40 BUFIO: 51 DIRIO: 15 FAULTS: 170
$
--------------------------------------------------------------------------------
HEADER_TYPE
The HEADER_TYPE command specifies the header type of the output DTI file.
--------------------------------------------------------------------------------
FORMAT: HEADER_TYPE type
--------------------------------------------------------------------------------
Command parameters:
type
A DTI header type keyword chosen from:
--------------------------------------------------------------------------------
DESCRIPTION:
The HEADER_TYPE allows the user to specify the header type of the output DTI file which contains the DTM grid.
By default TRIGRID generates a 'LSLA' type DTI file having WORD (16 bit integer) post values.
For a detailed description of the layout and content of DTI file header types see the DTILIB section of the MATRIX Reference Manual.
The default LSLA type DTI header contains only the matrix X and Y extent, Z range and the X and Y grid interval.
Due to the general purpose nature of TRIGRID it is not possible to collect from the user, and validate, all the complex information required to complete a military TED4 or UHL1 DTI header. Instead TRIGRID puts into a TED4 or UHL1 header the same information as for a LSLA type DTI. If output is to a TED4 type DTI file, the Latitude and Longitude origin and the Latitude and Longitude bounding rectangle values are inserted into the DSI record. These values are taken from the WINDOW command arguments. It is assumed that the triangulation units are tenths of seconds of arc.
The user is left to use the MATRIX package utility DTIPATCH to set up missing information.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
TRIGRID> HEADER_TYPE TED4<CR>
TRIGRID>
--------------------------------------------------------------------------------
HELP
Give help on a subject
--------------------------------------------------------------------------------
FORMAT: HELP subject
--------------------------------------------------------------------------------
Command parameters:
subject
The subject on which help is required
--------------------------------------------------------------------------------
Description:
The HELP command looks the rest of the line up in the DTMCREATE HELP library. This library contains a brief summary of the operation of each command.
The information is looked up in the TRIGRID section of the DTMCREATE help library, LSL$HELP:DTMCREATE.HLB.
--------------------------------------------------------------------------------
Messages:
Where required, warning messages are output via the VMS LBR$OUTPUT_HELP utility.
--------------------------------------------------------------------------------
Examples:
TRIGRID> HELP RETURN<CR>
RETURN
Restores command input from an indirect file to SYS$COMMAND.
A typical application is to allow the user to use an indirect command file to set up those run time defaults which are constant within a flowline and then return to input from the terminal (or batch stream) for the run specific commands. To do this RETURN must be the last command in the indirect command file.
TRIGRID>
--------------------------------------------------------------------------------
PAUSE
Pauses TRIGRID execution.
--------------------------------------------------------------------------------
FORMAT: PAUSE
--------------------------------------------------------------------------------
Command parameters: None.
--------------------------------------------------------------------------------
DESCRIPTION:
Pauses TRIGRID execution and issues a prompt for a carriage return to continue execution. This command is designed for use in software demonstration situations.
--------------------------------------------------------------------------------
Messages: None.
--------------------------------------------------------------------------------
Examples:
TRIGRID> PAUSE<CR>
--------------------------------------------------------------------------------
Quit from TRIGRID.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
The QUIT command causes TRIGRID to exit immediately, closing all input
files and closing and deleting all output files.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
TRIGRID> QUIT<CR>
--------------------------------------------------------------------------------
Restores command input from an indirect file to SYS$COMMAND.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Restores command input from an indirect file to SYS$COMMAND.
A typical application is to allow the user to use an indirect command file
to set up those run time defaults which are constant within a flowline and then
return to input from the terminal (or batch stream) for the run specific
commands. To do this RETURN must be the last command in the indirect command
file.
--------------------------------------------------------------------------------
The following messages are specific to the RETURN command:
RETURN command detected - returning to terminal input
RETURN command ignored - command input is already from terminal
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Shows current status of TRIGRID option and parameter settings.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
subject
The subject that is to be displayed, chosen from:
--------------------------------------------------------------------------------
SHOW command enables the user to examine the current status of TRIGRID
options and parameter settings.
--------------------------------------------------------------------------------
TRIGRID issues the following message if the SHOW command is specified
without an argument:
This feature can be used to advantage if the user wishes to quickly
determine for which items the SHOW facility is available.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
SHOW DATA_TYPE enables the user to examine the current setting for
the DATA_TYPE command.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
SHOW DATA_TYPE enables the user to examine the current setting for
the DATA_TYPE command. This determines the data type of the output DTI file.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Shows current status of TRIGRID option settings.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
SHOW ENABLE enables the user to examine the current status of TRIGRID
processing options that are set or unset using the ENABLE and DISABLE commands.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Shows current TRIGRID input and output files.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
SHOW FILES enables the user to examine the current status of TRIGRID
input files.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
SHOW HEADER_TYPE enables the user to examine the current setting for
the HEADER_TYPE command.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
SHOW HEADER_TYPE enables the user to examine the current setting for
the HEADER_TYPE command. This determines the header type of the output DTI
file.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Shows current status of TRIGRID Z-limits.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
SHOW LIMITS enables the user to examine the current status of TRIGRID
Z-limits parameters set using the LIMITS commands.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Shows current status of TRIGRID DTI file sidelength.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
SHOW SIDELENGTH enables the user to examine the current status of TRIGRID
DTI file sidelength parameters set using the SIDELENGTH or the combination of
SIZE and WINDOW commands.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Shows current status of TRIGRID output DTI file SIZE.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
SHOW SIZE enables the user to examine the current status of TRIGRID
output DTI file SIZE parameters set using the SIZE or the combination of
SIDELENGTH and WINDOW commands.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Shows current status of TRIGRID window units as set using the UNITS
command.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Shows current status of TRIGRID window units as set using the UNITS
command.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Shows current triangulation and DTM window values.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Shows current triangulation and DTM window values.
The units of the WINDOW command parameters are set using the UNITS
command. By default metre units are assumed. If it is more convenient
to specify the window in latitude and longitude the sexagesimal lat
long values may be supplied after specifying a UNITS LATLONG command.
This assumes that the data read in from the DTI and IFF files uaing TRIANG
were in units of tenths second of arc. A similar assumption is made for UNITS
SECONDS.
The SHOW WINDOW command displays the window values in the
units currently selected by the UNITS command. No projection transformation
is performed, so the unwise user could easily specify that the window
be shown as latitude longitude despite the fact that his data are in
metres!
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
_$ TRIGRID<CR>
DTMCREATE module TRIGRID of 13:53:27 3-FEB-89
TRIGRID> SHOW WINDOW<CR>
Window units are metres
DTM WINDOW currently undefined
Triangulation coverage currently unknown
--------------------------------------------------------------------------------
Specifies the spacing between the columns and rows of the output DTM.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
x-sidelength
The spacing between DTM posts along the X axis (columns).
y-sidelength
The spacing between DTM posts up the Y axis (rows). If this parameter
is omitted TRIGRID assumes equal X and Y sidelength values.
--------------------------------------------------------------------------------
The SIDELENGTH command enables the user to specify the spacing between
the columns and rows of the output DTM. The SIDELENGTH command arguments
should be specified in the units used for the triangulation.
If a SIZE command has already been issued then the SIZE values will
be overridden by new size values calculated when WINDOW is set using:
Over-riding SIZE settings
If the WINDOW is set, the number of rows and columns to cover
completely (possibly with some overlap) the specified area is
calculated. The results of this calculation will be displayed:
You may use the SIDELENGTH and WINDOW commands in combination as
often as you wish until the desired model characteristics are achieved.
--------------------------------------------------------------------------------
The following messages are specific to the SIDELENGTH command:
*** WARNING *** You must have at least 3 rows and 3 columns in your DTM
*** WARNING *** You must specify at least one argument
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Specifies the number of columns and rows of the output DTM.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
ncols
The number of columns (X-axis) in the output DTM.
nrows
The number of rows (Y-axis) in the output DTM. If this parameter
is omitted TRIGRID assumes equal X and Y SIZE values.
--------------------------------------------------------------------------------
The SIZE command enables the user to explicitly set the number of
columns and rows in the output DTM.
If you have already issued a SIDELENGTH command then the sidelength
values that you specified will be replaced by the values calculated from
WINDOW divided by the number of rows and number of columns and the message:
Over-riding SIDELENGTH settings
If you have already specified values for the WINDOW then TRIGRID
will calculate the cell sidelength required to give you the the
number of rows and columns specified by the SIZE command and the
results of this calculation will be displayed:
You may use the SIZE and WINDOW commands in combination as
often as you wish until the desired model characteristics are achieved.
--------------------------------------------------------------------------------
The following messages are specific to the SIZE command:
*** WARNING *** You must have at least 3 rows and 3 columns in your DTM
*** WARNING *** You must specify at least one argument
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
The SPAWN command enables you to create a subprocess while within TRIGRID.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
command-line
Specifies a DCL command string to be executed as if typed in response to
a '$' prompt. When the command completes, the subprocess terminates and control
is returned to TRIGRID. The command string cannot exceed 80 characters.
--------------------------------------------------------------------------------
The SPAWN command enables you to create a subprocess while within TRIGRID.
When the subprocess terminates control is returned to TRIGRID.
--------------------------------------------------------------------------------
The following warning messages are specific to the SPAWN command:
*** WARNING *** SPAWN requires a valid DCL command line
*** ERROR *** Unable to spawn command, returning to TRIGRID
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
The TRIANGLE_LIMITS arguments set limits for the interpolation function
selected for DTM post estimation within the individual triangles.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
real1
Undershoot limit for individual triangles. This is the amount
(measured in the model Z value units) that an interpolation within the triangle
may fall under the range of heights given by the values at the vertices of the
triangle. A suggested limit is approx 1/3 contour interval. Default is 300000,
i.e. no effectively limit!
real2
Overshoot limit for individual triangles. This is the amount
(measured in the model Z value units) that an interpolation within the triangle
may exceed the range of heights given by the values at the vertices of the
triangle. A suggested limit is approx 1 contour interval. Default is 300000,
i.e. no effectively limit!
--------------------------------------------------------------------------------
By default TRIGRID applies no limits to post height estimation.
The undershoot and overshoot limits for individual triangles define how
far an interpolation within the triangle may fall below or above the range of
heights given by the values at the vertices of the triangle. These
undershoot and overshoot limits are automatically modified by the ENABLE
AUTO_LIMITS command when appropriate node feature flags are detected. For
example, a triangle which has one or more nodes flagged as "river" nodes will
be allowed no interpolation undershoot at all.
No triangle limits are applied if the linear facet interpolation option is
selected as the interpolation is restricted to the triangle facet plane itself.
The same effect can be achieved (rather extravagantly) by setting
both the undershoot and overshoot triangle limits to 0.0 and then using
the SMOOTH patch interpolation option!
--------------------------------------------------------------------------------
The following messages are specific to the TRIANGLE_LIMITS command:
*** WARNING *** You must specify lower and upper limit arguments
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Specifies the units of measurement that will be used when defining
the DTM window using the WINDOW command.
The command also controls the units of measurement which will be used
when displaying DTI file header details.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
units
A keyword defining the measurement units, chosen from:
--------------------------------------------------------------------------------
The UNITS command enables the user to specify in what units of measurement
he wishes to define the DTM window using the WINDOW
command, or in what units of measurement details from the header of the DTI
file are displayed.
By default metre units are assumed.
If UNITS SECONDS or UNITS LATLONG are used it is assumed that
the data read in from the _.DTA and _.NOD files using FILEIN commands are in
units of tenth seconds of arc.
UNITS METRES (the default) or UNITS PROJECTION assume that
the the data read in using FILEIN commands are in metres or projection units.
Remember that TRIGRID assumes that if
UNITS SECONDS or UNITS LATLONG are selected the basic units in the _.DTA snd .
NOD files are tenth seconds arc.
The UNITS command does not affect the values specified as arguments to
the SIDELENGTH command. These should be expressed in terms of the basic units
held in the _.NOD and _.DTA files (i.e. tenth second arc units in the case of
geographical SECONDS or LATLONG). In the case of UNITS LATLONG, window values
should be expressed as south-west Latitude Longitude north-east
Latitude Longitude, not Longitude Latitude. The SHOW
WINDOW command will reflect the window extent in both LATLONG units
and tenth seconds arc.
--------------------------------------------------------------------------------
The following error messages are specific to the UNITS command:
--------------------------------------------------------------------------------
$ TRIGRID<CR>
_.DTA file LSL$SOURCE_ROOT:[DTMCREATE.TRIGRID]WEEPY_.DTA;8 opened for read
_.NOD file LSL$SOURCE_ROOT:[DTMCREATE.TRIGRID]WEEPY_.NOD;8 opened for read
_.DER file LSL$SOURCE_ROOT:[DTMCREATE.TRIGRID]WEEPY_.DER;8 opened for read
TRIGRID> UNITS LATLONG<CR>
TRIGRID> SHOW WINDOW<CR>
Window units are latlong (degrees, minutes and seconds)
Triangulation coverage SW: 4 45 00N 13 44 20E NE: 4 49 00N 13 46 50E
(SW: 494600.00 171000.00 NE: 496100.00 173400.00)
DTM WINDOW currently undefined.
TRIGRID> WINDOW 4 45 00N 13 45 00 E 4 50 00N 13 46 00E<CR>
TRIGRID> SIDELENGTH 10<CR>
X and Y call side lengths assumed equal ( 10.000 10.000 )
Window units are latlong (degrees, minutes and seconds)
Triangulation coverage SW: 4 45 00N 13 44 20E NE: 4 49 00N 13 46 50E
(SW: 494600.00 171000.00 NE: 496100.00 173400.00)
Triangulation window SW: 13 45 00N 4 45 00E NE: 13 46 00N 4 50 00E
(SW: 171000.00 495000.00 NE: 174000.00 495600.00)
Which with a side length of 10.000 in X and 10.000 in Y
gives 61 rows and 301 columns in the dtm
TRIGRID> SHOW WINDOW<CR>
Window units are latlong (degrees, minutes and seconds)
Triangulation coverage SW: 4 45 00N 13 44 20E NE: 4 49 00N 13 46 50E
(SW: 494600.00 171000.00 NE: 496100.00 173400.00)
Triangulation window SW: 13 45 00N 4 45 00E NE: 13 46 00N 4 50 00E
(SW: 171000.00 495000.00 NE: 174000.00 495600.00)
TRIGRID>
--------------------------------------------------------------------------------
Suspend processing for the specified number of seconds.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
seconds
The number (floating point) of seconds for which TRIGRID processing is
to be suspended.
--------------------------------------------------------------------------------
The WAIT command causes processing to be suspended for a specified
number of seconds. It is designed for use in software demonstration
situations and is of no value in a production flowline.
--------------------------------------------------------------------------------
The following warning message is specific to the WAIT command:
*** WARNING *** You must specify the number of seconds to wait
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Specifies the limits of the triangulation area to be gridded.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
xmin ymin
The coordinates of the bottom left hand corner of the defining rectangle.
xmax ymax
The coordinates of the top right hand corner of the defining rectangle.
--------------------------------------------------------------------------------
The WINDOW command is used to define rectangular limits to the area of
triangulation to be gridded into a DTI file. The limits must be specified
in the order bottom left hand (or south west) corner, then top right hand
(or north east) corner.
The WINDOW command can be used to clip data from a triangulation.
There is only one restriction on the WINDOW grid coverage allowed
relative to the triangulation extent. The grid DTM must have a minimum of 3
columns and 3 rows. The user may specify that the grid DTM WINDOW extends
beyond the triangulation area. Of course there are no original data points
for interpolation in the resulting marginal areas and the proclivities of a
poorly controlled mathematical surface may not truly represent the real world!
If the user is unsure of the triangulation (X,Y) extent a SHOW
WINDOW command will supply this information assuming that the triangulation
files have previously been opened with the FILEIN command.
The WINDOW command is obligatory.
--------------------------------------------------------------------------------
The following warning messages are specific to the WINDOW command:
*** WINDOW **** is still unset, please respecify the WINDOW command
*** ERROR **** window values define a zero width window
*** ERROR **** window values define a zero height window
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
The ZLIMITS arguments set overall model top and bottom z-limits for the
interpolation function selected for DTM post estimation.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
real1
The absolute lower range limit for the whole DTM. No posts in the DTM
will be allowed to have Z values below this value. The default is 0.0
real2
The absolute upper range limit for the whole DTM. No posts in the DTM
will be allowed to have Z values above this value. The default is 300000.0
i.e. effectively no limit!
--------------------------------------------------------------------------------
By default TRIGRID applies no limits to post height estimation.
The ZLIMITS command specifies lower and upper absolute range limits to
enable the user to force a base and ceiling value for the whole model which
the interpolation cannot exceed or fall under. This is particularly useful for
models containing areas of sea as the lower limit can be set to zero ensuring
that the sea cannot receive negative post values under any circumstances. A
model whose highest area forms a plateau can be similarly controlled.
--------------------------------------------------------------------------------
The following messages are specific to the ZLIMITS command:
*** WARNING *** You must specify lower and upper limit arguments
--------------------------------------------------------------------------------
$ TRIGRID<CR>
DTMCREATE module TRIGRID of 14:02:31 3-FEB-89
TRIGRID> @TESTCMD<CR>
Command input now being read from SYS$DISK:[]TESTCMD.COM;0
TRIGRID> FILEIN WEEPY
_.DTA file LSL$SOURCE_ROOT:[DTMCREATE.TRIGRID]WEEPY_.DTA;9 opened for read
_.NOD file LSL$SOURCE_ROOT:[DTMCREATE.TRIGRID]WEEPY_.NOD;9 opened for read
_.DER file LSL$SOURCE_ROOT:[DTMCREATE.TRIGRID]WEEPY_.DER;9 opened for read
TRIGRID> ZLIMITS 150 500
TRIGRID> TRIANGLE
TRIGRID> ENABLE DIAGNOSTICS
TRIGRID> WINDOW 494600.00 171000.00 496100.00 173400.00
TRIGRID> SIDELENGTH 10 10
Window units are metres
Triangulation coverage SW: 494600.00 171000.00 NE: 496100.00 173400.00
Triangulation window SW: 494600.00 171000.00 NE: 496100.00 173400.00
Which with a side length of 10.00 in X and 10.00 in Y
gives 241 rows and 151 columns in the dtm
TRIGRID> SHOW ENABLE
AUTO_LIMITS ......................................... On
DIAGNOSTICS ......................................... On
GRAPHICS ............................................ Off
SMOOTH .............................................. On
(Smooth patch interpolation)
NINT ................................................ On
ORTHOGONAL .......................................... Off
TRACE ............................................... Off
TRIGRID> SHOW LIMITS
Individual triangle undershoot limit ................. 5.000
Individual triangle overshoot limit .................. 15.000
Whole DTM lower z-value limit ........................ 150.000
Whole DTM upper z-value limit ........................ 500.000
Input files:
_.DTA file: LSL$SOURCE_ROOT:[DTMCREATE.TRIGRID]WEEPY_.DTA;9
_.NOD file: LSL$SOURCE_ROOT:[DTMCREATE.TRIGRID]WEEPY_.NOD;9
_.DER file: LSL$SOURCE_ROOT:[DTMCREATE.TRIGRID]WEEPY_.DER;9
Output file:
The DTI output file is undefined
TRIGRID> SHOW FILES
Input files:
_.DTA file: LSL$SOURCE_ROOT:[DTMCREATE.TRIGRID]WEEPY_.DTA;9
_.NOD file: LSL$SOURCE_ROOT:[DTMCREATE.TRIGRID]WEEPY_.NOD;9
_.DER file: LSL$SOURCE_ROOT:[DTMCREATE.TRIGRID]WEEPY_.DER;9
Output file:
The DTI output file is undefined
TRIGRID> SHOW WINDOW
Window units are metres
Triangulation coverage SW: 494600.00 171000.00 NE: 496100.00 173400.00
Triangulation window SW: 494600.00 171000.00 NE: 496100.00 173400.00
TRIGRID> GO
*** WARNING *** The following commands must be given
before processing can begin:
1) WINDOW
2) SIZE (or SIDELENGTH)
3) FILEIN
4) FILEOUT
*** WARNING *** Indirect file error - returning to terminal input
TRIGRID> FILEOUT TESTDTM<CR>
TRIGRID> GO<CR>
+----------------------------------------------------------------+
| |
| Reading in data and point in box markers |
| |
+----------------------------------------------------------------+
*** WARNING *** No projection information available for DTI header
+----------------------------------------------------------------+
| |
| Reading slope information |
| |
+----------------------------------------------------------------+
+----------------------------------------------------------------+
| |
| Opening and initialising DTI file |
| |
+----------------------------------------------------------------+
DTI file LSL$DATA_ROOT:[LSL.DTI]TESTDTM.DTI;0 opened for write
File : LSL$DATA_ROOT:[LSL.DTI]TESTDTM.DTI;0
Header : LSLA Data: WORD
Units are metres
Matrix Coverage SW: 0.00 0.00 NE: 199.50 199.50
Matrix Interval E: 2.10 N: 1.50
Value Range : 0 to 0
+----------------------------------------------------------------+
| |
| Generating DTM grid |
| |
+----------------------------------------------------------------+
ELAPSED: 0 00:00:10.96 CPU: 0:00:00.94 BUFIO: 14 DIRIO: 25 FAULTS: 347
This example shows a sequence of TRIGRID commands used to generate a
DTI output file having a 'LSLA' type header and word integer post
values.
TRIGRID introduces itself by giving the full name and creation date of
the current version of the program. The user has chosen to issue the TRIGRID
commands by use of an indirect command file using the @file-spec facility.
After successfully opening the specified command file,
SYS$DISK:[]TEST_CMD.COM; TRIGRID issues a message indicating the file-spec
used. All command input will be taken from this file until end
of file is detected, a command error is detected, a RETURN command is
detected, or a GO command results in successful termination of the run.
The first command specifies that input is to be from a file
called WEEPY. Only a file-name is supplied and TRIGRID parses this
against the user's current default device and directory specification. This
results in the file specification
These files are opened in turn and a message indicating successful
opening issued.
The ZLIMITS command specifies that no DTM post values are to be generated
below 100 or above 500 height units. The height units were originally set in
TRIANG.
The TRIANGLE_LIMITS command is used to set the undershoot (5)
and overshoot limits (15) for individual triangles. These limits define how
far an interpolation within the triangle may fall below or above the range of
heights given by the values at the vertices of the triangle. The
undershoot and overshoot are automatically modified by the ENABLE AUTO_LIMITS
command when appropriate node feature flags are detected. For example,
a triangle which has one or more nodes flagged as "river" nodes will
be allowed no interpolation undershoot at all. AUTO_LIMITS are enabled by
default on program startup and must be explicitly disabled if not
required.
As this program run is to be used as an example, the user
has used the ENABLE DIAGNOSTICS command to cause TRIGRID to output
diagnostic messages. Where a processing stage may take a long time, the
selection of diagnostics will cause messages indicating percentage progress
to be output. In the interests of compactness, these percentage progress
messages are not shown in this example.
The WINDOW command specifies the area of the triangulation that is to be
gridded into a DTI file. There is only one restriction on the grid coverage
allowed relative to the triangulation extent. The grid DTM must have
a minimum of 3 columns and 3 rows. The user may specify that the grid
DTM WINDOW extends beyond the triangulation area. Of course there
are no original data points for interpolation in the resulting marginal
areas and the proclivities of a poorly controlled mathematical surface may not
truly represent the real world!
If the user is unsure of the triangulation (X,Y) extent a SHOW
WINDOW command will supply this information assuming that the triangulation
files have previously been opened with the FILEIN command.
With the SIDELENGTH command the user has elected to specify explicit
(X,Y) DTM inter-post sidelengths rather than specify the WINDOW and then a
definitive grid size. TRIGRID calculates the DTM grid size to be 241 rows and
151 columns.
The SHOW commands enable the user to examine the current settings
for all the TRIGRID run time options. What the user has failed to notice from
this listing is the fact that he has yet to specify an output file
specification with the FILEOUT command.
The user, believing that all is set up for this run, specifies the GO
command to commence TRIGRID processing. TRIGRID performs checks that all the
obligatory commands have been specified and discovers an omission. The warning
message indicates the 4 obligatory commands that must be issued before
TRIGRID processing can be started. The GO command is ignored. As command
input was from indirect command file, TRIGRID issues a further warning
message, closes the indirect file and prompts for further commands at the
terminal.
The user, realising that he has not specified a FILEOUT command, now does
so. The missing parts from the file-spec supplied are taken from the default
LSL$DTI:DTI.DTI;0. Satisfied with this, he reissues the GO command, which is
this time accepted. TRIGRID processing begins. Messages indicating the start
of each major processing stage are output.
The warning that no projection information is available for the DTI header
is issued because TRIANG could find no projection information to put into
the input _.NOD and _.DTA files when forming the triangulation. Input must
have been from IFF files with unset type 2 MDs (Map Descriptor) or DTI files
without projection records. This will not affect the TRIGRID run, but the
DTI file header information should be checked carefully and the DTI
file projection record possibly set up using DTITRANS.
After opening the output DTI file, its header is
printed to the terminal. From this it is evident that the default file header
type is 'LSLA' and the default DTI file post data type is word (16 bit)
integer.
The run completed successfully. DCL symbol $STATUS is set to SS$_NORMAL,
normal successful completion. The DTM grid in the DTI file may now be viewed
using DTIVIEW.
See trigridmsg.html generated from TRIGRIDMSG.RNO.
Press
TRIGRID>
QUIT COMMAND
QUIT
FORMAT: QUIT
Command parameters: None.
Description:
Messages: None.
Examples:
ELAPSED: 00:05:25.84 CPU: 0:00:05.71 BUFIO: 281 DIRIO: 46 FAULTS: 263
_$
RETURN COMMAND
RETURN
FORMAT: RETURN
Command parameters: None.
DESCRIPTION:
Messages:
Examples:
TRIGRID> @FLOW2<CR>
TRIGRID> ENABLE DIAGNOSTICS
TRIGRID> RETURN
TRIGRID>
SHOW COMMAND
SHOW
FORMAT: SHOW subject
Command parameters:
DATA_TYPE ENABLE FILES HEADER_TYPE LIMITS SIDELENGTH
SIZE UNITS WINDOW
DESCRIPTION:
Messages:
*** ERROR *** Specifying command SHOW
Available SHOW command qualifiers are:
DATA_TYPE ENABLE FILES HEADER_TYPE LIMITS SIDELENGTH
SIZE UNITS WINDOW
Examples:
$ TRIGRID<CR>
DTMCREATE module TRIGRID of 14:02:31 3-FEB-89
TRIGRID> SHOW<CR>
*** ERROR *** Specifying command SHOW
Available SHOW command qualifiers are:
DATA_TYPE ENABLE FILES HEADER_TYPE LIMITS SIDELENGTH
SIZE UNITS WINDOW
TRIGRID> SHOW ENABLE ! examine current option settings<CR>
AUTO_LIMITS ......................................... On
DIAGNOSTICS ......................................... Off
GRAPHICS ............................................ Off
SMOOTH .............................................. On
(Smooth patch interpolation)
NINT ................................................ On
ORTHOGONAL .......................................... Off
TRACE ............................................... Off
TRIGRID>
SHOW DATA_TYPE COMMAND
SHOW DATA_TYPE
FORMAT: SHOW DATA_TYPE
Command parameters: None.
DESCRIPTION:
Messages: None.
Examples:
$ TRIGRID<CR>
DTMCREATE module TRIGRID of 17:02:12 23-JAN-89
TRIGRID> SHOW DATA_TYPE ! examine current data_type settings<CR>
DTI data type ....................................... WORD
TRIGRID>
SHOW ENABLE COMMAND
SHOW ENABLE
FORMAT: SHOW ENABLE
Command parameters: None.
DESCRIPTION:
Messages: None.
Examples:
$ TRIGRID<CR>
DTMCREATE module TRIGRID of 17:02:12 23-JAN-89
TRIGRID> SHOW ENABLE ! examine current option settings<CR>
TRIGRID>
SHOW FILES COMMAND
SHOW FILES
FORMAT: SHOW FILES
Command parameters: None.
DESCRIPTION:
Messages: None.
Examples:
$ TRIGRID<CR>
DTMCREATE module TRIGRID of 17:02:12 23-JAN-89
TRIGRID> SHOW FILES ! examine files<CR>
Input files:
The input files are undefined
Output file:
The DTI output file is undefined
TRIGRID> FILEOUT EXAMPLE ! open output DTI file<CR>
TRIGRID> SHOW FILES ! examine input file-specs<CR>
Input files:
The input files are undefined
Output file:
LSL$DATA_ROOT:[LSL.DTI]EXAMPLE.DTI;0
(DTI file window or size are currently undefined)
TRIGRID> FILEIN SW100230 ! get input files<CR>
_.DTA file DUA3:[DEMONSTRATION]SW100230_.DTA;6 opened for read
_.NOD file DUA3:[DEMONSTRATION]SW100230_.NOD;6 opened for read
_.DER file DUA3:[DEMONSTRATION]SW100230_.DER;6 opened for read
TRIGRID> SHOW FILES ! examine input file-specs<CR>
Input files:
_.DTA file: DUA3:[DEMONSTRATION]SW100230_.DTA;6
_.NOD file: DUA3:[DEMONSTRATION]SW100230_.NOD;6
_.DER file: DUA3:[DEMONSTRATION]SW100230_.DER;6
Output file:
LSL$DATA_ROOT:[LSL.DTI]EXAMPLE.DTI;0
(DTI file window or size are currently undefined)
TRIGRID>
SHOW HEADER_TYPE COMMAND
SHOW HEADER_TYPE
FORMAT: SHOW HEADER_TYPE
Command parameters: None.
DESCRIPTION:
Messages: None.
Examples:
$ TRIGRID<CR>
DTMCREATE module TRIGRID of 17:02:12 23-JAN-89
TRIGRID> SHOW HEADER_TYPE ! examine current data_type settings<CR>
DTI header type ...................................... LSLA
TRIGRID>
SHOW LIMITS COMMAND
SHOW LIMITS
FORMAT: SHOW LIMITS
Command parameters: None.
DESCRIPTION:
Messages: None.
Examples:
$ TRIGRID<CR>
DTMCREATE module TRIGRID of 17:02:12 23-JAN-89
TRIGRID> SHOW LIMITS ! examine LIMITS settings<CR>
No individual triangle interpolation limits will be applied
No whole DTM Z-limits will be applied
TRIGRID>
SHOW SIDELENGTH COMMAND
SHOW SIDELENGTH
FORMAT: SHOW SIDELENGTH
Command parameters: None.
DESCRIPTION:
Messages: None.
Examples:
$ TRIGRID<CR>
DTMCREATE module TRIGRID of 17:02:12 23-JAN-89
TRIGRID> SHOW SIDELENGTH ! examine sidelength settings<CR>
X-sidelength ........................................ Unset
Y-sidelength ........................................ Unset
TRIGRID> SIDELENGTH 4.0 4.0 ! set x and y sidelength <CR>
TRIGRID> SHOW SIDELENGTH ! examine sidelength settings<CR>
X-sidelength ........................................ 4.0
Y-sidelength ........................................ 4.0
TRIGRID>
SHOW SIZE COMMAND
SHOW SIZE
FORMAT: SHOW SIZE
Command parameters: None.
DESCRIPTION:
Messages: None.
Examples:
$ TRIGRID<CR>
DTMCREATE module TRIGRID of 17:02:12 23-JAN-89
TRIGRID> SHOW SIZE ! examine size settings<CR>
Number of columns ................................... Unset
Number of rows ...................................... Unset
TRIGRID> SIZE 801 401 ! set x and y sidelength <CR>
TRIGRID> SHOW SIZE ! examine sidelength settings<CR>
Number of columns ................................... 801
Number of rows ...................................... 401
TRIGRID>
SHOW UNITS COMMAND
SHOW UNITS
FORMAT: SHOW UNITS
Command parameters: None.
DESCRIPTION:
Messages: None.
Examples:
_$ TRIGRID<CR>
DTMCREATE module TRIGRID of 13:53:27 3-FEB-89
TRIGRID> SHOW UNITS<CR>
Window to be specified in metres
TRIGRID>
SHOW WINDOW COMMAND
SHOW WINDOW
FORMAT: SHOW WINDOW
Command parameters: None.
DESCRIPTION:
Messages: None.
Examples:
TRIGRID>
SIDELENGTH COMMAND
SIDELENGTH
FORMAT: SIDELENGTH x-sidelength y-sidelength
Command parameters:
DESCRIPTION:
NUMBER OF COLUMNS = X WINDOW LENGTH/ X_SIDELENGTH +1.5
NUMBER OF ROWS = Y WINDOW LENGTH/ Y_SIDELENGTH +1.5
and the message:
will appear.
Window units are metres
Triangulation coverage SW: 'real' 'real' NE: 'real' 'real'
Triangulation window SW: 'real' 'real' NE: 'real' 'real'
Which with a side length of 10.00 in X and 10.00 in Y
gives 'integer' rows and 'integer' columns in the dtm
Messages:
Examples:
TRIGRID> SIDELENGTH 40.0 50.0<CR>
TRIGRID>
SIZE COMMAND
SIZE
FORMAT: SIZE ncols nrows
Command parameters:
DESCRIPTION:
will appear.
Window units are metres
Triangulation coverage SW: 'real' 'real' NE: 'real' 'real'
Triangulation window SW: 'real' 'real' NE: 'real' 'real'
Which with a side length of 10.00 in X and 10.00 in Y
gives 'integer' rows and 'integer' columns in the dtm
Messages:
Examples:
TRIGRID> SIZE 101 201<CR>
TRIGRID>
SPAWN COMMAND
SPAWN
FORMAT: SPAWN command-line
Command parameters:
DESCRIPTION:
Messages:
Examples:
TRIGRID> SPAWN DIRECTORY *_.DTA;*<CR>
Directory DUA3:[DTMCREATE.ACCEPTANCE_TESTS]
TEST1_.DTA;1 8/8 18-AUG-1987 07:56 [LSL,TIM]
TEST2_.DTA;2 7/8 18-AUG-1987 17:17 [LSL,TIM]
TEST2_.DTA;1 7/8 18-AUG-1987 17:07 [LSL,TIM]
Total of 3 files, 22/24 blocks.
TRIGRID>
TRIANGLE_LIMITS COMMAND
TRIANGLE_LIMITS
FORMAT: TRIANGLE_LIMITS real1 real2
COMMAND PARAMETERS:
Description:
Messages:
Lower limit, upper limit?
Examples:
TRIGRID> SHOW LIMITS<CR>
No individual triangle interpolation limits will be applied
No whole DTM Z-limits will be applied
TRIGRID> TRIANGLE_LIMITS 3.0 10.0<CR>
TRIGRID> SHOW LIMITS<CR>
Individual triangle undershoot limit ................. 3.000
Individual triangle overshoot limit .................. 10.00
Whole DTM lower z-value limit ........................ Unset
Whole DTM upper z-value limit ........................ Unset
TRIGRID>
UNITS COMMAND
UNITS
FORMAT: UNITS units
Command parameters:
METRES Metres on the ground
LATLONG Latitude and Longitude
(in degrees, minutes and seconds)
SECONDS Seconds of arc
PROJECTION Projection units
DESCRIPTION:
The UNITS command should be given before specifying the DTM
window the user wishes to specify the window in non-metre units.
Messages:
*** ERROR *** Specifying command UNITS
Command qualifiers are METRES,PROJECTION,SECONDS or LATLONG
Examples:
DTMCREATE module TRIGRID of 14:28:22 20-JAN-89
TRIGRID> FILEIN WEEPY<CR>
WAIT COMMAND
WAIT
FORMAT: WAIT seconds
Command parameters:
DESCRIPTION:
Messages:
Examples:
TRIGRID> WAIT 4.0<CR>
TRIGRID>
WINDOW COMMAND
WINDOW
FORMAT: WINDOW xmin ymin xmax ymax
Command parameters:
DESCRIPTION:
Messages:
*** WARNING **** Unable to read WINDOW arguments
Examples:
TRIGRID> WINDOW 0.0 0.0 120.0 120.0<CR>
TRIGRID>
ZLIMITS COMMAND
ZLIMITS
FORMAT: ZLIMITS real1 real2
COMMAND PARAMETERS:
Description:
Messages:
Lower limit, upper limit?
Examples:
TRIGRID> ZLIMITS 150.0 500.0<CR>
TRIGRID> SHOW LIMITS<CR>
Individual triangle undershoot limit ................. Unset
Individual triangle overshoot limit .................. Unset
Whole DTM lower z-value limit ........................ 150.000
Whole DTM upper z-value limit ........................ 500.000
TRIGRID>
EXAMPLES
EXAMPLES
LSL$SOURCE_ROOT:[DTMCREATE.TRIGRID]WEEPY_.DTA
This is used as a generic specification for all three input files required by
TRIGRID, a _.DTA file containing the inter_node relationships, a _.NOD
file containing the nodes themselves and a _.DER file containing slope
derivatives.