numpy.select — NumPy v1.11 Manual (original) (raw)

numpy.select(condlist, choicelist, default=0)[source]¶

Return an array drawn from elements in choicelist, depending on conditions.

Parameters:	condlist : list 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. choicelist : list of ndarrays The list of arrays from which the output elements are taken. It has to be of the same length as condlist. default : scalar, optional The element inserted in output when all conditions evaluate to False.
Returns:	output : ndarray 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.

Parameters:

condlist : list 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. choicelist : list of ndarrays The list of arrays from which the output elements are taken. It has to be of the same length as condlist. default : scalar, optional The element inserted in output when all conditions evaluate to False.

Returns:

output : ndarray 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.

Examples

x = np.arange(10) condlist = [x<3, x>5] choicelist = [x, x**2] np.select(condlist, choicelist) array([ 0, 1, 2, 0, 0, 0, 36, 49, 64, 81])