- numpy.select(condlist, choicelist, default=0)¶
Return an array drawn from elements in choicelist, depending on conditions.
- condlistlist of bool ndarrays
The list of conditions which determine from which array in choicelist the output elements are taken. When multiple conditions are satisfied, the first one encountered in condlist is used.
- choicelistlist of ndarrays
The list of arrays from which the output elements are taken. It has to be of the same length as condlist.
- defaultscalar, optional
The element inserted in output when all conditions evaluate to False.
The output at position m is the m-th element of the array in choicelist where the m-th element of the corresponding array in condlist is True.
>>> x = np.arange(6) >>> condlist = [x<3, x>3] >>> choicelist = [x, x**2] >>> np.select(condlist, choicelist, 42) array([ 0, 1, 2, 42, 16, 25])
>>> condlist = [x<=4, x>3] >>> choicelist = [x, x**2] >>> np.select(condlist, choicelist, 55) array([ 0, 1, 2, 3, 4, 25])