/usr/share/doc/libplplot12/examples/perl/x26.pl is in libplplot-dev 5.10.0+dfsg-1.
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The actual contents of the file can be viewed below.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 | #! /usr/bin/env perl
#
# $Id: x26.pl 11730 2011-04-29 22:16:08Z huntd $
#
# -*- coding: utf-8; -*-
#
# Demo x26 for the PLplot PDL binding
#
# Multi-lingual version of the first page of example 4.
#
# Copyright (C) 2006 Alan Irwin
# Copyright (C) 2006 Andrew Ross
#
# Thanks to the following for providing translated strings for this example:
# Valery Pipin (Russian)
#
# 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
# This example designed just for devices (e.g., psttfc and the
# cairo-related devices) that use the pango and fontconfig libraries. The
# best choice of glyph is selected by fontconfig and automatically rendered
# by pango in way that is sensitive to complex text layout (CTL) language
# issues for each unicode character in this example. Of course, you must
# have the appropriate TrueType fonts installed to have access to all the
# required glyphs.
# Translation instructions: The strings to be translated are given by
# x_label, y_label, alty_label, title_label, and line_label below. The
# encoding used must be UTF-8.
# The following strings to be translated involve some scientific/mathematical
# jargon which is now discussed further to help translators.
# (1) dB is a decibel unit, see http://en.wikipedia.org/wiki/Decibel .
# (2) degrees is an angular measure, see
# http://en.wikipedia.org/wiki/Degree_(angle) .
# (3) low-pass filter is one that transmits (passes) low frequencies.
# (4) pole is in the mathematical sense, see
# http://en.wikipedia.org/wiki/Pole_(complex_analysis) . "Single Pole"
# means a particular mathematical transformation of the filter function has
# a single pole, see
# http://ccrma.stanford.edu/~jos/filters/Pole_Zero_Analysis_I.html .
# Furthermore, a single-pole filter must have an inverse square decline
# (or -20 db/decade). Since the filter plotted here does have that
# characteristic, it must by definition be a single-pole filter, see also
# http://www-k.ext.ti.com/SRVS/Data/ti/KnowledgeBases/analog/document/faqs/1p.htm
# (5) decade represents a factor of 10, see
# http://en.wikipedia.org/wiki/Decade_(log_scale) .
# SYNC: x26c.c 1.1
use PDL;
use PDL::Graphics::PLplot;
use Math::Trig qw [pi];
use Getopt::Long;
@x_label = (
"Frequency",
"Частота"
);
@y_label = (
"Amplitude (dB)",
"Амплитуда (dB)"
);
@alty_label = (
"Phase shift (degrees)",
"Фазовый сдвиг (градусы)"
);
@legend_text = (
[ "Amplitude", "Phase shift" ],
[ "Амплитуда", "Фазовый сдвиг" ],
);
@title_label = (
"Single Pole Low-Pass Filter",
"Однополюсный Низко-Частотный Фильтр"
);
@line_label = (
"-20 dB/decade",
"-20 dB/десяток"
);
sub main {
# Parse and process command line arguments
plParseOpts (\@ARGV, PL_PARSE_SKIP | PL_PARSE_NOPROGRAM);
# Initialize plplot
plinit();
plfont(2);
# Make log plots using two different styles.
for (my $i=0; $i<scalar(@x_label); $i++) {
plot1(0, $x_label[$i], $y_label[$i], $alty_label[$i],
$legend_text[$i], $title_label[$i], $line_label[$i]);
}
plend();
}
sub plot1 {
my ($type, $x_label, $y_label, $alty_label, $legend_text, $title_label, $line_label) = @_;
pladv(0);
# Set up data for log plot
my $f0 = 1.0;
my $freql = -2.0 + sequence(101)/20.0;
my $freq = 10**$freql;
my $ampl = 20.0 * log10(1.0 / sqrt(1.0 + ($freq / $f0)**2));
my $phase = -(180.0 / pi) * atan($freq / $f0);
plvpor(0.15, 0.85, 0.1, 0.9);
plwind(-2.0, 3.0, -80.0, 0.0);
# Try different axis and labelling styles.
plcol0(1);
if ($type == 0) {
plbox(0.0, 0,0.0, 0, "bclnst", "bnstv");
}
if ($type == 1) {
plbox(0.0, 0, 0.0, 0, "bcfghlnst", "bcghnstv");
}
# Plot ampl vs freq
plcol0(2);
plline($freql, $ampl);
plcol0(2);
plptex(1.6, -30.0, 1.0, -20.0, 0.5, $line_label);
# Put labels on
plcol0(1);
plmtex(3.2, 0.5, 0.5, "b", $x_label);
plmtex(2.0, 0.5, 0.5, "t", $title_label);
plcol0(2);
plmtex(5.0, 0.5, 0.5, "l", $y_label);
# For the gridless case, put phase vs freq on same plot
if ($type == 0) {
plcol0(1);
plwind(-2.0, 3.0, -100.0, 0.0);
plbox(0.0, 0, 30.0, 3, "", "cmstv");
plcol0(3);
plline($freql, $phase);
plstring($freql, $phase, "*");
plcol0(3);
plmtex(5.0, 0.5, 0.5, "r", $alty_label);
}
# Draw a legend
my @opt_array = (PL_LEGEND_LINE, PL_LEGEND_LINE | PL_LEGEND_SYMBOL);
my @text_colors = (2, 3);
my @text = ("Amplitude", "Phase shift");
my @line_colors = (2, 3);
my @line_styles = (1, 1);
my @line_widths = (1, 1);
my @symbol_colors = (3, 3); # ???
my @symbol_scales = (1, 1); # ???
my @symbol_numbers = (4, 4);# ???
my @symbols = ('*', '*'); # ???
plscol0a(15, 32, 32, 32, 0.70);
my ($legend_width, $legend_height) = pllegend(
PL_LEGEND_BACKGROUND | PL_LEGEND_BOUNDING_BOX, 0,
0.0, 0.0, 0.1, 15,
1, 1, 0, 0,
$nlegend = 2, \@opt_array,
1.0, 1.0, 2.0,
1., \@text_colors, $legend_text,
0, 0, 0, 0,
\@line_colors, \@line_styles, \@line_widths,
\@symbol_colors, \@symbol_scales, \@symbol_numbers, \@symbols);
}
main();
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