#! /usr/bin/env perl
#
# Demo x19 for the PLplot PDL binding
#
# Illustrates backdrop plotting of world, US maps.
#
# Copyright (C) 2004 Rafael Laboissiere
#
# 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
# SYNC: x19c.c 1.10
use PDL;
use PDL::Graphics::PLplot;
use Math::Trig qw [pi];
#--------------------------------------------------------------------------
# main
#
# Shows two views of the world map.
#--------------------------------------------------------------------------
# Parse and process command line arguments
plParseOpts (\@ARGV, PL_PARSE_SKIP | PL_PARSE_NOPROGRAM);
# Longitude (x) and latitude (y)
my $miny = -70;
my $maxy = 80;
plinit ();
# Cartesian plots
# Most of world
my $minx = 190;
my $maxx = 190 + 360;
# Setup a custom latitude and longitude-based scaling function.
plslabelfunc(\&geolocation_labeler);
plcol0 (1);
plenv ($minx, $maxx, $miny, $maxy, 1, 70);
plmap ($minx, $maxx, $miny, $maxy, 0, "usaglobe");
# The Americas
$minx = 190;
$maxx = 340;
plcol0 (1);
plenv ($minx, $maxx, $miny, $maxy, 1, 70);
plmap ($minx, $maxx, $miny, $maxy, 0, "usaglobe");
# Clear the labeling function
plslabelfunc(0);
# Polar, Northern hemisphere
$minx = 0;
$maxx = 360;
plenv (-75, 75, -75, 75, 1, -1);
plmap ($minx, $maxx, $miny, $maxy, \&mapform19, "globe");
pllsty (2);
plmeridians (10.0, 10.0, 0.0, 360.0, -10.0, 80.0, \&mapform19);
# Polar, Northern hemisphere, this time with a PLplot-wide transform
plstransform(\&mapform19);
pllsty(1);
plenv(-75, 75, -75, 75, 1, -1);
# No need to set the map transform here as the global transform will be
# used.
plmap($minx, $maxx, $miny, $maxy, 0, "globe");
pllsty(2);
plmeridians(10.0, 10.0, 0.0, 360.0, -10.0, 80.0, 0);
# Show Baltimore, MD on the map
plcol0(2);
plssym(0.0, 2.0);
my $x = pdl (-76.6125);
my $y = pdl (39.2902778);
plpoin($x, $y, 18);
plssym(0.0, 1.0);
plptex(-76.6125, 43.0, 0.0, 0.0, 0.0, "Baltimore, MD");
# For perl, this is how the global transform is cleared
plstransform(0);
plend ();
#--------------------------------------------------------------------------
# Subroutines
#--------------------------------------------------------------------------
#--------------------------------------------------------------------------
# mapform19
#
# Defines specific coordinate transformation for example 19.
# Not to be confused with mapform in src/plmap.c.
# $x and $y are the coordinates to be plotted. They can be either
# perl scalars (when used as an argument to plstransform) or PDLs
# (when used as an argument to plmeridians or plmap)
#--------------------------------------------------------------------------
sub mapform19 {
my ($x, $y) = @_;
my $radius = 90.0 - $y;
my $xp = $radius * cos ($x * pi / 180);
my $yp = $radius * sin ($x * pi / 180);
return ($xp, $yp);
}
#--------------------------------------------------------------------------
# geolocation_labeler
#
# A custom axis labeling function for longitudes and latitudes.
#--------------------------------------------------------------------------
sub geolocation_labeler {
my ($axis, $value, $length) = @_;
my ($direction_label, $label_val);
if (($axis == PL_Y_AXIS) && $value == 0) {
return "Eq";
} elsif ($axis == PL_Y_AXIS) {
$label_val = $value;
$direction_label = ($label_val > 0) ? " N" : " S";
} elsif ($axis == PL_X_AXIS) {
my $times = floor((abs($value) + 180.0 ) / 360.0);
$label_val = ($value < 0) ? $value + 360.0 * $times : $value - 360.0 * $times;
$direction_label = ($label_val > 0) ? " E"
: ($label_val < 0) ? " W"
: "";
}
return substr (sprintf ("%.0f%s", abs($label_val), $direction_label), 0, $length);
}