VL_NNSOFTMAXLOSS - CNN combined softmax and logistic loss.

Y = VL_NNSOFTMAX(X, C) applies the softmax operator followed by the logistic loss the data X. X has dimension H x W x D x N, packing N arrays of W x H D-dimensional vectors.

C contains the class labels, which should be integers in the range 1 to D. C can be an array with either N elements or with dimensions H x W x 1 x N dimensions. In the fist case, a given class label is applied at all spatial locations; in the second case, different class labels can be specified for different locations.

DZDX = VL_NNSOFTMAXLOSS(X, C, DZDY) computes the derivative of the block projected onto DZDY. DZDX and DZDY have the same dimensions as X and Y respectively.