Programmer Guide/Command Reference/EVAL/pginit: Difference between revisions
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Check or initialise a polygon stream. | Check or initialise a polygon stream. | ||
;Usage:<code> | ;Usage:<code>pginit(<var>X</var> {, <var>N</var>=0, {number}<var>E</var>=0} )</code> | ||
:;<var>X</var>:A [[../#polygons|closed point-list]] or a [[../#polygons|polygon-stream]] defining one or more polygons. | :;<var>X</var>:A [[../#polygons|closed point-list]] or a [[../#polygons|polygon-stream]] defining one or more polygons. | ||
:;<var>N</var>:The requested number of simple polygons: | :;<var>N</var>:The requested number of simple polygons: | ||
| Line 13: | Line 13: | ||
::*no simple polygons can be found or one of the detected polygons is invalid | ::*no simple polygons can be found or one of the detected polygons is invalid | ||
::*<var>N</var>>0 and the number of polygons defined by <var>X</var> is not equal to <var>N</var> | ::*<var>N</var>>0 and the number of polygons defined by <var>X</var> is not equal to <var>N</var> | ||
;See also: [[../ | ;See also: [[../pgget|pgget]], [[../pgitest|pgitest]], [[../pgiline|pgiline]], [[../pgxgrid|pgxgrid]], [[../pgsplit|pgsplit]], [[../pgtrans|pgtrans]], [[../pghull|pghull]] | ||
[[../#Functions|<function list>]] | [[../#Functions|<function list>]] | ||
Revision as of 13:45, 18 April 2011
Check or initialise a polygon stream.
- Usage
pginit(X {, N=0, {number}E=0} )- X
- A closed point-list or a polygon-stream defining one or more polygons.
- N
- The requested number of simple polygons:
N<=0 undefined, polygons are counted during initialization N>0 exactly N simple polygons must be contained in X
- E
- The maximum error for polygon simplification. If E<=0 the simplification is skipped.
- Result
- A polygon-stream P containing all simple-polygons defined by X. The function failes if:
- no simple polygons can be found or one of the detected polygons is invalid
- N>0 and the number of polygons defined by X is not equal to N
