The program psxyz allows us to plot three-dimensional
symbols, including columnar plots. As a simple demonstration,
we will convert a gridded netCDF of bathymetry into an
ASCII
table and use the height information to draw a
2-D histogram in a 3-D perspective view. Our gridded
bathymetry file is called topo.grd and covers the region
from 0 to 5 °E and 0 to 5 °N. Depth ranges from
-5000 meter to sea-level. We produce the illustration by
running this command:
#!/bin/csh
# GMT EXAMPLE 08
#
# Purpose: Make a 3-D bar plot
# GMT progs: grd2xyz, pstext, psxyz
# Unix progs: echo, rm
grd2xyz guinea_bay.nc | \
psxyz -B1/1/1000:"Topography (m)"::.ETOPO5:WSneZ+ -R-0.1/5.1/-0.1/5.1/-5000/0 \
-P -JM5i -JZ6i -E200/30 -So0.0833333ub-5000 -U"Example 8 in Cookbook" \
-Wthinnest -Glightgray -K >! example_08.ps
echo '0.1 4.9 24 0 1 TL This is the surface of cube' | pstext -R -J -JZ -Z0 -E200/30 -O \
>> example_08.ps
\rm -f .gmt*
The output can be viewed in Figure 7.8.