"""
grdclip - Change the range and extremes of grid values.
"""
import xarray as xr
from pygmt.clib import Session
from pygmt.helpers import (
GMTTempFile,
build_arg_string,
fmt_docstring,
kwargs_to_strings,
use_alias,
)
[docs]@fmt_docstring
@use_alias(
G="outgrid",
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, **kwargs):
r"""
Sets 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 : 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.
{R}
above : str or list or tuple
[*high*, *above*].
Set all data[i] > *high* to *above*.
below : str or list or tuple
[*low*, *below*].
Set all data[i] < *low* to *below*.
between : str or list or tuple
[*low*, *high*, *between*].
Set all data[i] >= *low* and <= *high* to *between*.
new : str or list or tuple
[*old*, *new*].
Set all data[i] == *old* to *new*. This is mostly useful when
your data are known to be integer values.
{V}
"""
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 "G" not in kwargs.keys(): # if outgrid is unset, output to tempfile
kwargs.update({"G": tmpfile.name})
outgrid = kwargs["G"]
arg_str = " ".join([infile, build_arg_string(kwargs)])
lib.call_module("grdclip", arg_str)
if outgrid == tmpfile.name: # if user did not set outgrid, return DataArray
with xr.open_dataarray(outgrid) as dataarray:
result = dataarray.load()
_ = result.gmt # load GMTDataArray accessor information
else:
result = None # if user sets an outgrid, return None
return result