Pixel-registered surface documentation

Added by Gregory 10 months ago

GMT5.4.2 surface (and certain earlier) versions accept the -r flag, and produce pixel-registered grids with the appropriate decimation factors.
However the online help "Bugs" insists that only gridline-registered grids may be produced, and should be resampled to produce pixel-registered grids.
"Note that only gridline registration is possible with surface. If you need a pixel-registered grid you can resample a gridline registered grid using grdsample -T."