numpy.ma.putmask

ma.putmask(a, mask, values)

Changes elements of an array based on conditional and input values.

This is the masked array version of numpy.putmask, for details see numpy.putmask.

See also

numpy.putmask

Notes

Using a masked array as values will not transform a ndarray into a MaskedArray.

Examples

>>> import numpy as np
>>> arr = [[1, 2], [3, 4]]
>>> mask = [[1, 0], [0, 0]]
>>> x = np.ma.array(arr, mask=mask)
>>> np.ma.putmask(x, x < 4, 10*x)
>>> x
masked_array(
  data=[[--, 20],
        [30, 4]],
  mask=[[ True, False],
        [False, False]],
  fill_value=999999)
>>> x.data
array([[10, 20],
       [30,  4]])