numpy.ma.where#
- ma.where(condition, x=<no value>, y=<no value>)[source]#
Return a masked array with elements from x or y, depending on condition.
Note
When only condition is provided, this function is identical to
nonzero
. The rest of this documentation covers only the case where all three arguments are provided.- Parameters:
- conditionarray_like, bool
Where True, yield x, otherwise yield y.
- x, yarray_like, optional
Values from which to choose. x, y and condition need to be broadcastable to some shape.
- Returns:
- outMaskedArray
An masked array with
masked
elements where the condition is masked, elements from x where condition is True, and elements from y elsewhere.
See also
numpy.where
Equivalent function in the top-level NumPy module.
nonzero
The function that is called when x and y are omitted
Examples
>>> x = np.ma.array(np.arange(9.).reshape(3, 3), mask=[[0, 1, 0], ... [1, 0, 1], ... [0, 1, 0]]) >>> x masked_array( data=[[0.0, --, 2.0], [--, 4.0, --], [6.0, --, 8.0]], mask=[[False, True, False], [ True, False, True], [False, True, False]], fill_value=1e+20) >>> np.ma.where(x > 5, x, -3.1416) masked_array( data=[[-3.1416, --, -3.1416], [--, -3.1416, --], [6.0, --, 8.0]], mask=[[False, True, False], [ True, False, True], [False, True, False]], fill_value=1e+20)