I have tried to multipliate a number with a matrix, the problem is the next: if i do this operation:
Mat deriv_1 = Mat(groundTruth.size[1], groundTruth.size[0], CV_64F);
double number = 1 / 256;
deriv_1 = -number*(groundTruth - probs);// (-1 / M)*(groundTruth - probs);
all the numbers of matrix are 0 but if i do this:
Mat deriv_1 = Mat(groundTruth.size[1], groundTruth.size[0], CV_64F);
deriv_1 = -0.0039*(groundTruth - probs);// (-1 / M)*(groundTruth - probs);
the result is correct. i dont know why.
