Programmer Guide/Command Reference/EVAL/pgget: Difference between revisions
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Extract a polygon from a [[../#polygons|closed point-list]] or a [[../#polygons|polygon-stream]]. | Extract a polygon from a [[../#polygons|closed point-list]] or a [[../#polygons|polygon-stream]]. | ||
---- | ---- | ||
;Usage 1:<code>pginit(<var>X</var>) | ;Usage 1:<code>pginit(<var>X</var>)</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. | ||
;Result 1: The number of [[../#polygons|simple polygons]] ''N'' stored in ''X''. If the result is '''0''', ''X'' contains no valid polygons. | ;Result 1: The number of [[../#polygons|simple polygons]] ''N'' stored in ''X''. If the result is '''0''', ''X'' contains no valid polygons. | ||
---- | ---- | ||
;Usage 2:<code>pginit(<var>X</var>, <var>I</var>, <var>fmt</var>) | ;Usage 2:<code>pginit(<var>X</var>, <var>I</var>, <var>fmt</var>)</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>I</var>:The index of the polygon to be returned; 0 <= ''I'' < ''N'' (= <code>pgget(''X'')</code>) | :;<var>I</var>:The index of the polygon to be returned; 0 <= ''I'' < ''N'' (= <code>pgget(''X'')</code>) | ||
Revision as of 07:25, 20 April 2011
Extract a polygon from a closed point-list or a polygon-stream.
- Usage 1
pginit(X)- X
- A closed point-list or a polygon-stream defining one or more polygons.
- Result 1
- The number of simple polygons N stored in X. If the result is 0, X contains no valid polygons.
- Usage 2
pginit(X, I, fmt)- X
- A closed point-list or a polygon-stream defining one or more polygons.
- I
- The index of the polygon to be returned; 0 <= I < N (=
pgget(X)) - fmt
- The format of the result.:
fmt=0 ... return the I-th polygon of X as polygon-stream fmt=1 ... return the polygon-stream header (a 8x2 matrix) of the I-th polygon of X
- Result 2
- The I-th polygon stored in X in the format selected by fmt.
on. If E<=0 the simplification is skipped.
