- pygmt.grdcut(grid, *, outgrid=None, region=None, projection=None, extend=None, circ_subregion=None, verbose=None, z_subregion=None, coltypes=None, **kwargs)
Extract subregion from a grid.
Produce a new
outgridfile which is a subregion of
grid. The subregion is specified with
region; the specified range must not exceed the range of
extend). If in doubt, run
pygmt.grdinfoto check range. Alternatively, define the subregion indirectly via a range check on the node values or via distances from a given point. Finally, you can give
projectionfor oblique projections to determine the corresponding rectangular
regionthat will give a grid that fully covers the oblique domain.
Full option list at https://docs.generic-mapping-tools.org/latest/grdcut.html
G = outgrid
J = projection
N = extend
R = region
S = circ_subregion
V = verbose
Z = z_subregion
f = coltypes
outgrid (str or None) – The name of the output netCDF file with extension .nc to store the grid in.
circ_subregion (str) – lon/lat/radius[unit][+n]. Specify an origin (lon and lat) and radius; append a distance unit and we determine the corresponding rectangular region so that all grid nodes on or inside the circle are contained in the subset. If +n is appended we set all nodes outside the circle to NaN.
z_subregion (str) – [min/max][+n|N|r]. Determine a new rectangular region so that all nodes outside this region are also outside the given z-range [-inf/+inf]. To indicate no limit on min or max only, specify a hyphen (-). Normally, any NaNs encountered are simply skipped and not considered in the range-decision. Append +n to consider a NaN to be outside the given z-range. This means the new subset will be NaN-free. Alternatively, append +r to consider NaNs to be within the data range. In this case we stop shrinking the boundaries once a NaN is found [Default simply skips NaNs when making the range decision]. Finally, if your core subset grid is surrounded by rows and/or columns that are all NaNs, append +N to strip off such columns before (optionally) considering the range of the core subset for further reduction of the area.
Select verbosity level [Default is w], which modulates the messages written to stderr. Choose among 7 levels of verbosity:
q - Quiet, not even fatal error messages are produced
e - Error messages only
w - Warnings [Default]
t - Timings (report runtimes for time-intensive algorithms)
i - Informational messages (same as
c - Compatibility warnings
d - Debugging messages
coltypes (str) – [i|o]colinfo. Specify data types of input and/or output columns (time or geographical data). Full documentation is at https://docs.generic-mapping-tools.org/latest/gmt.html#f-full.
ret (xarray.DataArray or None) – Return type depends on whether the
outgridparameter is set:
outgridis not set
outgridis set (grid output will be stored in file set by
>>> import pygmt >>> # Load a grid of @earth_relief_30m data, with an x-range of 10 to 30, >>> # and a y-range of 15 to 25 >>> grid = pygmt.datasets.load_earth_relief( ... resolution="30m", region=[10, 30, 15, 25] ... ) >>> # Create a new grid from an input grid, with an x-range of 12 to 15, >>> # and a y-range of 21 to 24 >>> new_grid = pygmt.grdcut(grid=grid, region=[12, 15, 21, 24])