chainerx.sigmoid_cross_entropy¶
- chainerx.sigmoid_cross_entropy(x1, x2)¶
Element-wise cross entropy loss for pre-sigmoid activations.
- Parameters
x1 (ndarray) – An array whose (i, j)-th element indicates the unnormalized log probability of the j-th unit at the i-th example.
x2 (ndarray) – An array whose (i, j)-th element indicates a signed integer vector of ground truth labels 0 or 1. If
x2[i, j] == -1
, correspondingx1[i, j]
is ignored. Loss is zero if all ground truth labels are -1.
- Returns
An array of the cross entropy.
- Return type
Note
During backpropagation, this function propagates the gradient of the output array to the input array
x1
only.