This is great info for shading the grid image. It sounds like the functionality of grdgradient is essentially incorporated into the grdimage function. I recognize that the GMT documentation is the ultimate source of info, but it might be helpful for new users to see in the pyGMT manual that I=shading flag can accept “bool” or “str” (i.e. shading=True, or shading=’+a45+nt1’). Since the main GMT functions require users to use grdgradient first to create the netCDF and then use that as an input into grdimage, its unclear that grdimage does this shading on the fly.