"""
sph2grd - Compute grid from spherical harmonic coefficients
"""
from pygmt.clib import Session
from pygmt.helpers import (
GMTTempFile,
build_arg_string,
fmt_docstring,
kwargs_to_strings,
use_alias,
)
from pygmt.io import load_dataarray
__doctest_skip__ = ["sph2grd"]
[docs]@fmt_docstring
@use_alias(
G="outgrid",
I="spacing",
R="region",
V="verbose",
b="binary",
h="header",
i="incols",
r="registration",
x="cores",
)
@kwargs_to_strings(I="sequence", R="sequence", i="sequence_comma")
def sph2grd(data, **kwargs):
r"""
Create spherical grid files in tension of data.
Reads a spherical harmonics coefficient table with records of L, M,
C[L,M], S[L,M] and evaluates the spherical harmonic model on the
specified grid.
Full option list at :gmt-docs:`sph2grd.html`
{aliases}
Parameters
----------
data : str or {table-like}
Pass in data with L, M, C[L,M], S[L,M] values by
providing a file name to an ASCII data table, a 2D
{table-classes}.
outgrid : str or None
The name of the output netCDF file with extension .nc to store the grid
in.
{I}
{R}
{V}
{b}
{h}
{i}
{r}
{x}
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
>>> # Create a new grid from the remote file "EGM96_to_36.txt",
>>> # set the grid spacing to 1, and the region to "g"
>>> new_grid = pygmt.sph2grd(
... data="@EGM96_to_36.txt", spacing=1, region="g"
... )
"""
with GMTTempFile(suffix=".nc") as tmpfile:
with Session() as lib:
file_context = lib.virtualfile_from_data(check_kind="vector", data=data)
with file_context as infile:
if "G" not in kwargs: # if outgrid is unset, output to tempfile
kwargs.update({"G": tmpfile.name})
outgrid = kwargs["G"]
lib.call_module("sph2grd", build_arg_string(kwargs, infile=infile))
return load_dataarray(outgrid) if outgrid == tmpfile.name else None