takes a vector of indices and returns a vector of elements at those indices along the matrix.

returns biggest value from whole of the matrix

0 = rows, 1 = columns

minus value from all the elements

matrix multiplication

matrix vector addition

matrix vector addition operator

@brief Test function. Sums the output after activation_softmax has run on the output layer. Correct output is 1.0. * * @param[in] output_layer