(8) A 3-D histogram

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 xyz table and use the height information to draw a 2-D histogram in a 3-D perspective view. Our gridded bathymetry file is called guinea_bay.nc 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 Figure by running this script:

# Purpose:	Make a 3-D bar plot
# GMT modules:	grd2xyz, pstext, psxyz
# Unix progs:	echo, rm
gmt grd2xyz guinea_bay.nc | gmt psxyz -B1 -Bz1000+l"Topography (m)" -BWSneZ+b+tETOPO5 \
	-R-0.1/5.1/-0.1/5.1/-5000/0 -JM5i -JZ6i -p200/30 -So0.0833333ub-5000 -P \
	-Wthinnest -Glightgreen -K > $ps
echo '0.1 4.9 This is the surface of cube' | gmt pstext -R -J -JZ -Z0 \
	-F+f24p,Helvetica-Bold+jTL -p -O >> $ps

A 3-D histogram.