.\" Automatically generated by Pod::Man 4.07 (Pod::Simple 3.32) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. Capital omega is used to do unbreakable dashes and .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff, .\" nothing in troff, for use with C<>. .tr \(*W- .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode transform. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" .\" If the F register is >0, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .if !\nF .nr F 0 .if \nF>0 \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} .\} .\" ======================================================================== .\" .IX Title "Math::Polygon::Calc 3pm" .TH Math::Polygon::Calc 3pm "2016-12-28" "perl v5.24.1" "User Contributed Perl Documentation" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" Math::Polygon::Calc \- Simple polygon calculations .SH "INHERITANCE" .IX Header "INHERITANCE" .Vb 2 \& Math::Polygon::Calc \& is a Exporter .Ve .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 1 \& my @poly = ( [1,2], [2,4], [5,7], [1, 2] ); \& \& my ($xmin, $ymin, $xmax, $ymax) = polygon_bbox @poly; \& \& my $area = polygon_area @poly; \& MY $L = polygon_perimeter @poly; \& if(polygon_is_clockwise @poly) { ... }; \& \& my @rot = polygon_start_minxy @poly; .Ve .SH "DESCRIPTION" .IX Header "DESCRIPTION" This package contains a wide variaty of relatively easy polygon calculations. More complex calculations are put in separate packages. .SH "FUNCTIONS" .IX Header "FUNCTIONS" .IP "\fBpolygon_area\fR(LIST\-of\-$points)" 4 .IX Item "polygon_area(LIST-of-$points)" Returns the area enclosed by the polygon. The last point of the list must be the same as the first to produce a correct result. .Sp The algorithm was found at , and sounds: .Sp .Vb 1 \& A = abs( 1/2 * (x1y2\-x2y1 + x2y3\-x3y2 ...) .Ve .IP "\fBpolygon_bbox\fR(LIST\-of\-$points)" 4 .IX Item "polygon_bbox(LIST-of-$points)" Returns a list with four elements: (xmin, ymin, xmax, ymax), which describe the bounding box of the polygon (all points of the polygon are within that area. .IP "\fBpolygon_beautify\fR( [$options], LIST\-of\-$points )" 4 .IX Item "polygon_beautify( [$options], LIST-of-$points )" Polygons, certainly after some computations, can have a lot of horrible artifacts: points which are double, spikes, etc. This functions provided by this module beautify The optional \s-1HASH\s0 contains the \f(CW$options:\fR .Sp .Vb 3 \& \-Option \-\-Default \& remove_between \& remove_spikes .Ve .RS 4 .IP "remove_between => \s-1BOOLEAN\s0" 2 .IX Item "remove_between => BOOLEAN" Simple points in-between are always removed, but more complex points are not: when the line is not parallel to one of the axes, more intensive calculations must take place. This will only be done when this flags is set. \&\s-1NOT IMPLEMENTED YET\s0 .IP "remove_spikes => \s-1BOOLEAN\s0" 2 .IX Item "remove_spikes => BOOLEAN" .RE .RS 4 .RE .PD 0 .IP "\fBpolygon_centroid\fR(LIST\-of\-$points)" 4 .IX Item "polygon_centroid(LIST-of-$points)" .PD Returns the centroid location of the polygon. The last point of the list must be the same as the first to produce a correct result. .Sp The algorithm was found at \&\fIhttp://en.wikipedia.org/wiki/Centroid#Centroid_of_polygon\fR .IP "\fBpolygon_clockwise\fR(LIST\-of\-$points)" 4 .IX Item "polygon_clockwise(LIST-of-$points)" Be sure the polygon points are in clockwise order. .IP "\fBpolygon_contains_point\fR($point, LIST\-of\-$points)" 4 .IX Item "polygon_contains_point($point, LIST-of-$points)" Returns true if the point is inside the closed polygon. On an edge will be flagged as 'inside'. But be warned of rounding issues, caused by the floating-point calculations used by this algorithm. .IP "\fBpolygon_counter_clockwise\fR(LIST\-of\-$points)" 4 .IX Item "polygon_counter_clockwise(LIST-of-$points)" Be sure the polygon points are in counter-clockwise order. .ie n .IP "\fBpolygon_distance\fR($point, @polygon)" 4 .el .IP "\fBpolygon_distance\fR($point, \f(CW@polygon\fR)" 4 .IX Item "polygon_distance($point, @polygon)" [1.05] calculate the shortest distance between a point and any vertex of a closed polygon. .IP "\fBpolygon_equal\fR( ARRAY\-of\-$points, ARRAY\-of\-$points, [$tolerance] )" 4 .IX Item "polygon_equal( ARRAY-of-$points, ARRAY-of-$points, [$tolerance] )" Compare two polygons, on the level of points. When the polygons are the same but rotated, this will return false. See \fIpolygon_same()\fR. .IP "\fBpolygon_is_clockwise\fR(LIST\-of\-$points)" 4 .IX Item "polygon_is_clockwise(LIST-of-$points)" .PD 0 .IP "\fBpolygon_is_closed\fR($points)" 4 .IX Item "polygon_is_closed($points)" .IP "\fBpolygon_perimeter\fR(LIST\-of\-$points)" 4 .IX Item "polygon_perimeter(LIST-of-$points)" .PD The length of the line of the polygon. This can also be used to compute the length of any line: of the last point is not equal to the first, then a line is presumed; for a polygon they must match. .Sp This is simply Pythagoras. .Sp .Vb 1 \& $l = sqrt((x1\-x0)^2 + (y1\-y0)^2) + sqrt((x2\-x1)^2+(y2\-y1)^2) + ... .Ve .IP "\fBpolygon_same\fR( ARRAY\-of\-$points, ARRAY\-of\-$points, [$tolerance] )" 4 .IX Item "polygon_same( ARRAY-of-$points, ARRAY-of-$points, [$tolerance] )" Compare two polygons, where the polygons may be rotated wrt each other. This is (much) slower than \fIpolygon_equal()\fR, but some algorithms will cause un unpredictable rotation in the result. .IP "\fBpolygon_start_minxy\fR(LIST\-of\-$points)" 4 .IX Item "polygon_start_minxy(LIST-of-$points)" Returns the polygon, where the point which is closest to the left-bottom corner of the bounding box is made first. .IP "\fBpolygon_string\fR(LIST\-of\-$points)" 4 .IX Item "polygon_string(LIST-of-$points)" .SH "SEE ALSO" .IX Header "SEE ALSO" This module is part of Math-Polygon distribution version 1.05, built on December 28, 2016. Website: \fIhttp://perl.overmeer.net/geo/\fR .SH "LICENSE" .IX Header "LICENSE" Copyrights 2004,2006\-2016 by [Mark Overmeer]. For other contributors see ChangeLog. .PP This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See \fIhttp://www.perl.com/perl/misc/Artistic.html\fR