Source code for pygmt.src.grdsample

grdsample - Resample a grid onto a new lattice

from pygmt.clib import Session
from pygmt.helpers import (
from import load_dataarray

__doctest_skip__ = ["grdsample"]

[docs]@fmt_docstring @use_alias( G="outgrid", I="spacing", R="region", T="translate", V="verbose", f="coltypes", n="interpolation", r="registration", x="cores", ) @kwargs_to_strings(I="sequence", R="sequence") def grdsample(grid, **kwargs): r""" Change the registration, spacing, or nodes in a grid file. This reads a grid file and interpolates it to create a new grid file. It can change the registration with ``translate`` or ``registration``, change the grid-spacing or number of nodes with ``spacing``, and set a new sub-region using ``region``. A bicubic [Default], bilinear, B-spline or nearest-neighbor interpolation is set with ``interpolation``. When ``region`` is omitted, the output grid will cover the same region as the input grid. When ``spacing`` is omitted, the grid spacing of the output grid will be the same as the input grid. Either ``registration`` or ``translate`` can be used to change the grid registration. When omitted, the output grid will have the same registration as the input grid. Full option list at :gmt-docs:`grdsample.html` {aliases} Parameters ---------- grid : str or xarray.DataArray The file name of the input grid or the grid loaded as a DataArray. outgrid : str or None The name of the output netCDF file with extension .nc to store the grid in. {spacing} {region} translate : bool Translate between grid and pixel registration; if the input is grid-registered, the output will be pixel-registered and vice-versa. registration : str or bool [**g**\|\ **p**\ ]. Set registration to **g**\ ridline or **p**\ ixel. {verbose} {coltypes} {interpolation} {cores} 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 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, change the registration, >>> # and set both x- and y-spacing to 0.5 degrees >>> new_grid = pygmt.grdsample( ... grid=grid, translate=True, spacing=[0.5, 0.5] ... ) """ with GMTTempFile(suffix=".nc") as tmpfile: with Session() as lib: file_context = lib.virtualfile_from_data(check_kind="raster", data=grid) with file_context as infile: if (outgrid := kwargs.get("G")) is None: kwargs["G"] = outgrid = # output to tmpfile lib.call_module( module="grdsample", args=build_arg_string(kwargs, infile=infile) ) return load_dataarray(outgrid) if outgrid == else None