grdcut - Extract a subregion out of a .grd file
grdcut input_file.grd -Goutput_file.grd -Rwest/east/south/north[r] [ -V
grdcut will produce a new output_file.grd file which is a subregion of
input_file.grd. The subregion is specified with
-Rwest/east/south/north as in other programs; the specified range must
not exceed the range of input_file.grd. If in doubt, run grdinfo to
check range. Complementary to grdcut there is grdpaste, which will
join together two grdfiles along a common edge.
this is the input .grd format file.
this is the output .grd format file.
-R west, east, south, and north specify the Region of interest. To
specify boundaries in degrees and minutes [and seconds], use the
dd:mm[:ss] format. Append r if lower left and upper right map
coordinates are given instead of wesn. This defines the
subregion to be cut out.
-V Selects verbose mode, which will send progress reports to stderr
[Default runs "silently"].
Suppose you have used surface to grid ship gravity in the region
between 148E - 162E and 8N - 32N, and you do not trust the gridding
near the edges, so you want to keep only the area between 150E - 160E
and 10N - 30N, then:
grdcut grav_148_162_8_32.grd -Ggrav_150_160_10_30.grd -R150/160/10/30
grdpaste, grdinfo, gmt
Man(1) output converted with