The type of number expected can be ascertained from the format of the default.
These are used when entering the value of a code (e_.g_. units or projections).
Integers consist of an optional sign (+ or -) followed by a series of decimal digits.
These are used when entering real (single or double precision) numbers; e_.g_. when entering the value of a coordinate or the scale.
a integer - coerced to a real
a.b real format
a.bEc exponential format
a.bDc double precision exponential format
a.b/c.d rational format
The syntax of a real number may be more formally defined as:
<real number> ::= <unsigned real number> |
<sign><unsigned real number>
<unsigned real number> ::= <basic real number> |
<basic real number><exponent> |
<basic real number>'/'<basic real number>
<sign> ::= '+' | '-'
<basic real number> ::= <whole part> |
<fraction part> |
<whole part><fraction part>
<exponent> ::= 'E'<signed decimal number> |
'D'<signed decimal number>
<whole part> ::= <decimal number>
<fraction part> ::= '.'<decimal number>
<signed decimal number> ::= <decimal number> |
<sign><decimal number>
<decimal number> ::= <digit> |
<decimal number><digit>
<digit> ::= '0' | '1' | '2' | '3' | '4' |
'5' | '6' | '7' | '8' | '9'
These are used when projections require additional information, and that information is an angular quantity (e_.g_. the latitude of the origin).
They are also used when the /POINT qualifier has been given and projection code 100 and unit code 200 specified.
Angles can be specified in the format sDDD MM SS.SSS or DDD MM SS.SSSh where:
The following all represent the same angular value: -00 00 30.00 00 00 30.00 S 00 00 30 s 00 00.5 W 0.00833333 w