Selecting grid points
thinning
You can thin a dataset by specifying the thinning
parameter in the
open_dataset
function. The thinning
parameter depends on the
method
selected. The default (and only) method is “every-nth”, which
will mask out all but every Nth point, with N specified by the
thinning
parameter.
ds = open_dataset(dataset, thinning=N, method="every-nth")
Please note that the thinning will apply to all dimensions of the fields. So for 2D fields, the thinning will apply to both the latitude and longitude dimensions. For 1D fields, such as reduced Gaussian grids, the thinning will apply to the only dimension.
The following example shows the effect of thinning a dataset with a 1 degree resolution:

Thinning the dataset with thinning=4
will result in the following
dataset:

area
You can crop a dataset to a specific area by specifying the area in the
open_dataset
function. The area is specified as a list of four
numbers in the order (north, west, south, east)
. For example, to
crop a dataset to the area between 60N and 20N and 50W and 0E, you can
use:
ds = open_dataset(dataset, area=(60, -50, 20, 0))
Which will result in the following dataset:

Alternatively, you can specify another dataset as the area. In this case, the bounding box of the dataset will be used.
ds = open_dataset(dataset1, area=dataset2)