Our next and perhaps most business-like example presents a
three-dimensional bar graph plot showing the geographic
distribution of the membership in the American Geophysical
Union (AGU). The input data was taken from the January 2008 AGU
member directory and added up to give total members per
continent. We decide to plot a 3-D column centered on
each continent with a height that is proportional to the
logarithm of the membership. A log-scale is
used since the memberships vary by almost 3 orders of
magnitude. We choose a plain linear projection for the
basemap and add the columns and text on top. Our script that produces Figure 7.10 reads:
#!/bin/sh # GMT EXAMPLE 10 # # Purpose: Make 3-D bar graph on top of perspective map # GMT progs: pscoast, pstext, psxyz # Unix progs: $AWK, rm # ps=example_10.ps pscoast -Rd -JX8id/5id -Dc -Gblack -E200/40 -K -U"Example 10 in Cookbook" > $ps psxyz agu2008.d -R-180/180/-90/90/1/100000 -J -JZ2.5il -So0.3ib1 -Ggray -Wthinner \ -B60g60/30g30/a1p:Memberships:WSneZ -O -K -E200/40 >> $ps $AWK '{print $1, $2, 20, 0, 0, "RM", $3}' agu2008.d \ | pstext -Rd -J -O -K -E200/40 -Gwhite -Sthinner -D-0.2i/0 >> $ps echo "4.5 6 30 0 5 BC AGU 2008 Membership Distribution" | pstext -R0/11/0/8.5 -Jx1i -O >> $ps rm -f .gmt*