/usr/share/doc/libplplot12/examples/lua/x19.lua is in libplplot-dev 5.10.0+dfsg-1.
This file is owned by root:root, with mode 0o644.
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 | --[[ $Id: x19.lua 12532 2013-09-26 15:18:37Z andrewross $
Illustrates backdrop plotting of world, US maps.
Contributed by Wesley Ebisuzaki.
Copyright (C) 2008 Werner Smekal
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
--]]
-- initialise Lua bindings for PLplot examples.
dofile("plplot_examples.lua")
function map_transform(x,y)
radius = 90 - y
xt = radius * math.cos(x * math.pi / 180)
yt = radius * math.sin(x * math.pi / 180)
return xt, yt
end
--------------------------------------------------------------------------
-- mapform19
--
-- Defines specific coordinate transformation for example 19.
-- Not to be confused with mapform in src/plmap.c.
-- x[], y[] are the coordinates to be plotted.
--------------------------------------------------------------------------
function mapform19(n, x, y)
for i = 1, n do
x[i], y[i] = map_transform(x[i], y[i])
end
return x, y
end
-- "Normalize" longitude values so that they always fall between
-- -180.0 and 180.0
function normalize_longitude(lon)
if lon>=-180 and lon<=180 then
return lon;
else
times = math.floor((math.abs(lon)+180)/360)
if lon<0 then
return lon+360*times
else
return lon-360*times
end
end
end
-- A custom axis labeling function for longitudes and latitudes.
function geolocation_labeler(axis, value)
if axis==pl.PL_Y_AXIS then
label_val = value
if label_val>0 then
direction_label = " N"
else
if label_val<0 then
direction_label = " S"
else
direction_label = "Eq"
end
end
else
if axis==pl.PL_X_AXIS then
label_val = normalize_longitude(value);
if label_val>0 then
direction_label = " E"
else
if label_val<0 then
direction_label = " W"
else
direction_label = ""
end
end
end
end
if axis==pl.PL_Y_AXIS and value==0 then
-- A special case for the equator
label = direction_label
else
label = math.abs(label_val) .. direction_label
end
return label
end
--------------------------------------------------------------------------
-- main
--
-- Shows two views of the world map.
--------------------------------------------------------------------------
-- Parse and process command line arguments
x = {}
y = {}
pl.parseopts(arg, pl.PL_PARSE_FULL)
-- Longitude (x) and latitude (y)
miny = -70
maxy = 80
pl.init()
-- Cartesian plots
-- Most of world
minx = -170
maxx = minx+360
-- Setup a custom latitude and longitude-based scaling function.
pl.slabelfunc("geolocation_labeler");
pl.col0(1)
pl.env(minx, maxx, miny, maxy, 1, 70)
pl.map(nil, "usaglobe", minx, maxx, miny, maxy)
-- The Americas
minx = 190
maxx = 340
pl.col0(1)
pl.env(minx, maxx, miny, maxy, 1, 70)
pl.map(nil, "usaglobe", minx, maxx, miny, maxy)
-- Clear the labeling function
pl.slabelfunc(nil);
-- Polar, Northern hemisphere
minx = 0
maxx = 360
pl.env(-75., 75., -75., 75., 1, -1)
pl.map("mapform19", "globe", minx, maxx, miny, maxy)
pl.lsty(2)
pl.meridians("mapform19", 10, 10, 0, 360, -10, 80)
-- Polar, Northern hemisphere, this time with a PLplot-wide transform
minx = 0
maxx = 360
pl.stransform( "map_transform" )
pl.lsty( 1 )
pl.env( -75., 75., -75., 75., 1, -1 )
-- No need to set the map transform here as the global transform will be
-- used.
pl.map( nil, "globe", minx, maxx, miny, maxy )
pl.lsty( 2 );
pl.meridians( nil, 10.0, 10.0, 0.0, 360.0, -10.0, 80.0 )
-- Show Baltimore, MD on the map
pl.col0( 2 )
pl.ssym( 0.0, 2.0 )
x[1] = -76.6125
y[1] = 39.2902778
pl.poin( x, y, 18 )
pl.ssym( 0.0, 1.0 )
pl.ptex( -76.6125, 43.0, 0.0, 0.0, 0.0, "Baltimore, MD" )
-- For C, this is how the global transform is cleared
pl.stransform( );
pl.plend()
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