Source code for pygmt.src.grdclip

grdclip - Change the range and extremes of grid values.

from pygmt.clib import Session
from pygmt.helpers import build_arg_list, fmt_docstring, kwargs_to_strings, use_alias

__doctest_skip__ = ["grdclip"]

[docs] @fmt_docstring @use_alias( R="region", Sa="above", Sb="below", Si="between", Sr="new", V="verbose", ) @kwargs_to_strings( R="sequence", Sa="sequence", Sb="sequence", Si="sequence", Sr="sequence", ) def grdclip(grid, outgrid: str | None = None, **kwargs): r""" Set values in a grid that meet certain criteria to a new value. Produce a clipped ``outgrid`` or :class:`xarray.DataArray` version of the input ``grid`` file. The parameters ``above`` and ``below`` allow for a given value to be set for values above or below a set amount, respectively. This allows for extreme values in a grid, such as points below a certain depth when plotting Earth relief, to all be set to the same value. Full option list at :gmt-docs:`grdclip.html` {aliases} Parameters ---------- {grid} {outgrid} {region} above : str or list [*high*, *above*]. Set all data[i] > *high* to *above*. below : str or list [*low*, *below*]. Set all data[i] < *low* to *below*. between : str or list [*low*, *high*, *between*]. Set all data[i] >= *low* and <= *high* to *between*. new : str or list [*old*, *new*]. Set all data[i] == *old* to *new*. This is mostly useful when your data are known to be integer values. {verbose} Returns ------- ret: xarray.DataArray or None Return type depends on whether the ``outgrid`` parameter is set: - :class:`xarray.DataArray` if ``outgrid`` is not set - None if ``outgrid`` is set (grid output will be stored in file set by ``outgrid``) Example ------- >>> import pygmt >>> # Load a grid of @earth_relief_30m data, with a longitude range of >>> # 10° E to 30° E, and a latitude range of 15° N to 25° N >>> grid = pygmt.datasets.load_earth_relief( ... resolution="30m", region=[10, 30, 15, 25] ... ) >>> # Report the minimum and maximum data values >>> [,] [183.5, 1807.0] >>> # Create a new grid from an input grid. Set all values below 1,000 to >>> # 0 and all values above 1,500 to 10,000 >>> new_grid = pygmt.grdclip(grid=grid, below=[1000, 0], above=[1500, 10000]) >>> # Report the minimum and maximum data values >>> [,] [0.0, 10000.0] """ with Session() as lib: with ( lib.virtualfile_in(check_kind="raster", data=grid) as vingrd, lib.virtualfile_out(kind="grid", fname=outgrid) as voutgrd, ): kwargs["G"] = voutgrd lib.call_module( module="grdclip", args=build_arg_list(kwargs, infile=vingrd) ) return lib.virtualfile_to_raster(vfname=voutgrd, outgrid=outgrid)