#!/bin/sh
#		GMT EXAMPLE 25
#		$Id: job25.sh,v 1.8 2010/06/21 23:42:56 guru Exp $
#
# Purpose:	Display distribution of antipode types
# GMT progs:	gmtset, grdlandmask, grdmath, grd2xyz, gmtmath, grdimage, pscoast, pslegend
# Unix progs:	cat
#
# Create D minutes global grid with -1 over oceans and +1 over land
ps=example_25.ps
D=30
grdlandmask -Rg -I${D}m -Dc -A500 -N-1/1/1/1/1 -F -Gwetdry.nc
# Manipulate so -1 means ocean/ocean antipode, +1 = land/land, and 0 elsewhere
grdmath wetdry.nc DUP 180 ROTX FLIPUD ADD 2 DIV = key.nc
# Calculate percentage area of each type of antipode match.
grdmath -Rg -I${D}m -F Y COSD 60 $D DIV 360 MUL DUP MUL PI DIV DIV 100 MUL = scale.nc
grdmath key.nc -1 EQ 0 NAN scale.nc MUL = tmp.nc
grd2xyz tmp.nc -S -ZTLf > key.b
ocean=`gmtmath -bi1s -Ca -S key.b SUM UPPER RINT =`
grdmath key.nc 1 EQ 0 NAN scale.nc MUL = tmp.nc
grd2xyz tmp.nc -S -ZTLf > key.b
land=`gmtmath -bi1s -Ca -S key.b SUM UPPER RINT =`
grdmath key.nc 0 EQ 0 NAN scale.nc MUL = tmp.nc
grd2xyz tmp.nc -S -ZTLf > key.b
mixed=`gmtmath -bi1s -Ca -S key.b SUM UPPER RINT =`
# Generate corresponding color table
cat << END > key.cpt
-1.5	blue	-0.5	blue
-0.5	gray	0.5	gray
0.5	red	1.5	red
END
# Create the final plot and overlay coastlines
gmtset ANNOT_FONT_SIZE_PRIMARY +10p PLOT_DEGREE_FORMAT dddF
grdimage key.nc -Sn -JKs180/9i -B60/30:."Antipodal comparisons":WsNE -K -Ckey.cpt -Y1.2i \
	-U/-0.75i/-0.95i/"Example 25 in Cookbook" > $ps
pscoast -R -J -O -K -Wthinnest -Dc -A500 >> $ps
# Place an explanatory legend below
pslegend -R0/9/0/0.5 -Jx1i/-1i -O -Dx4.5/0/6i/0.3i/TC -Y-0.2i -Fthick >> $ps << END
N 3
S 0.15i s 0.2i red  0.25p 0.3i Terrestrial Antipodes [$land %]
S 0.15i s 0.2i blue 0.25p 0.3i Oceanic Antipodes [$ocean %]
S 0.15i s 0.2i gray 0.25p 0.3i Mixed Antipodes [$mixed %]
END
rm -f *.nc key.* .gmt*