/usr/share/doc/libplplot12/examples/perl/x27.pl is in libplplot-dev 5.10.0+dfsg-1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 | #! /usr/bin/env perl
# $Id: x27.pl 11730 2011-04-29 22:16:08Z huntd $
#
# Copyright (C) 2008 Doug Hunt
# Drawing "spirograph" curves - epitrochoids, cycolids, roulettes
# This file is part of PLplot.
#
# PLplot is free software; you can redistribute it and/or modify
# it under the terms of the GNU Library General Public License as published
# by the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# PLplot is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Library General Public License for more details.
#
# You should have received a copy of the GNU Library General Public License
# along with PLplot; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
#
use PDL;
use PDL::Graphics::PLplot;
use constant PI => 4*atan2(1,1);
plParseOpts (\@ARGV, PL_PARSE_SKIP | PL_PARSE_NOPROGRAM);
plinit ();
#
# Generates two kinds of plots:
# - construction of a cycloid (animated) (TBD)
# - series of epitrochoids and hypotrochoids
# R, r, p, N
# R and r should be integers to give correct termination of the
# angle loop using gcd.
# N.B. N is just a place holder since it is no longer used
# (because we now have proper termination of the angle loop).
my $params = [ [21.0, 7.0, 7.0, 3.0], # Deltoid
[21.0, 7.0, 10.0, 3.0],
[21.0, -7.0, 10.0, 3.0],
[20.0, 3.0, 7.0, 20.0],
[20.0, 3.0, 10.0, 20.0],
[20.0, -3.0, 10.0, 20.0],
[20.0, 13.0, 7.0, 20.0],
[20.0, 13.0, 20.0, 20.0],
[20.0,-13.0, 20.0, 20.0] ];
# Illustrate the construction of a cycloid
# TODO
#cycloid()
# Loop over the various curves
# First an overview, then all curves one by one
plssub(3, 3); # Three by three window
my $fill = 0;
foreach my $parm (@$params) {
pladv(0);
plvpor(0, 1, 0, 1);
spiro($parm, $fill);
}
pladv(0);
plssub(1, 1); # One window per curve
foreach my $parm (@$params) {
pladv(0);
plvpor(0, 1, 0, 1);
spiro($parm, $fill);
}
# Fill the curves
$fill = 1;
pladv( 0 );
plssub( 1, 1 ); # One window per curve
foreach my $parm (@$params) {
pladv( 0 );
plvpor(0, 1, 0, 1);
spiro( $parm, $fill);
}
# Don't forget to call plend() to finish off!
plend();
#--------------------------------------------------------------------------
# Calculate greatest common divisor following pseudo-code for the
# Euclidian algorithm at http://en.wikipedia.org/wiki/Euclidean_algorithm
sub gcd {
my ($a, $b) = @_;
$a = abs( $a );
$b = abs( $b );
while ( $b != 0 ) {
my $t = $b;
$b = $a % $b;
$a = $t;
}
return $a;
}
sub spiro {
my $params = shift;
my $fill = shift;
# Fill the coordinates
my $NPNT = 2000;
my $windings = abs($params->[1]) / gcd($params->[0], $params->[1]);
my $steps = int($NPNT/$windings);
my $dphi = 2.0*PI/$steps;
my $phi = sequence($windings*$steps+1) * $dphi;
my $phiw = ($params->[0]-$params->[1])/$params->[1]*$phi;
my $xcoord = ($params->[0]-$params->[1])*cos($phi) + $params->[2]*cos($phiw);
my $ycoord = ($params->[0]-$params->[1])*sin($phi) - $params->[2]*sin($phiw);
my ($xmin, $xmax) = $xcoord->minmax;
my ($ymin, $ymax) = $ycoord->minmax;
my $xrange_adjust = 0.15 * ($xmax - $xmin);
$xmin -= $xrange_adjust;
$xmax += $xrange_adjust;
my $yrange_adjust = 0.15 * ($ymax - $ymin);
$ymin -= $yrange_adjust;
$ymax += $yrange_adjust;
plwind($xmin, $xmax, $ymin, $ymax);
plcol0(1);
if ($fill) {
plfill ($xcoord, $ycoord);
} else {
plline ($xcoord, $ycoord);
}
}
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