verde.distance_mask¶

verde.distance_mask(data_coordinates, maxdist, coordinates=None, region=None, spacing=None, shape=None, **kwargs)[source]¶

Create a mask for points that are too far from the given data points.

Produces a mask array that is False when a point is more than maxdist from the closest data point and True otherwise.

The points that will be masked can be specified by their coordinates or by a region and shape/spacing, in which case a regular grid will be generated for the mask. If specifying a region, extra keyword arguments to this function will be passed along to verde.grid_coordinates.

Parameters:

data_coordinates : tuple of arrays: Same as coordinates but for the data points.
maxdist : float: The maximum distance that a point can be from the closest data point.
coordinates : None or tuple of arrays: Arrays with the coordinates of each point that will be masked. Should be in the following order: (easting, northing, vertical, …). Only easting and northing will be used, all subsequent coordinates will be ignored. If not given, the region and spacing or shape must be provided.
region : list = [W, E, S, N] or None: The boundaries of a given region in Cartesian or geographic coordinates.
shape : tuple = (n_north, n_east) or None: The number of points in the South-North and West-East directions, respectively.
spacing : float, tuple = (s_north, s_east), or None: The grid spacing in the South-North and West-East directions, respectively. A single value means that the spacing is equal in both directions.

Returns:

mask : array: The mask boolean array with the same shape as easting and northing.

Examples

>>> from verde import grid_coordinates
>>> region = (0, 5, -10, -5)
>>> spacing = 1
>>> coords = grid_coordinates(region, spacing=spacing)
>>> mask = distance_mask((2.5, -7.5), maxdist=2, coordinates=coords)
>>> print(mask)
[[False False False False False False]
 [False False  True  True False False]
 [False  True  True  True  True False]
 [False  True  True  True  True False]
 [False False  True  True False False]
 [False False False False False False]]
>>> mask = distance_mask((3.5, -7.5), maxdist=2, region=region,
...                      spacing=spacing)
>>> print(mask)
[[False False False False False False]
 [False False False  True  True False]
 [False False  True  True  True  True]
 [False False  True  True  True  True]
 [False False False  True  True False]
 [False False False False False False]]