(8) A 3-D histogram

The program plot3d 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. We also use the height information to set to color of each column via a CPT file. Our gridded bathymetry file is the 5 arc-minute global relief. Depth ranges from -5000 meter to sea-level. We produce the Figure by running this script:

using GMT

C = makecpt(color=:cubhelix, T=(-5000,0))
bar3(gmtread("@earth_relief_05m_g", region=(0,5,0,5)), region=(0,5,0,5,-5000,0), base=-5000,
     frame=(annot=1, axes=:WSneZ, title=:ETOPO5, cube=true),
     zaxis=(annot=1000, label="Topography (m)"), color=C,
     lw=:thinnest, proj=:Mercator, figsize=12, zsize=13, view=(200,30))
text!(mat2ds([0.1 4.7], "This is the surface of cube"), JZ=true, Z=0,
      font=(24,"Helvetica-Bold"), justify=:TL, show=true)