OpenCV 3.1 ANN predict returns nan

Question

I am trying to implement Neural network with OpenCV ANN Library. I had a working solution, but after upgrading to OpenCV 3.1 it stopped working. So I created a simplified co

Answer 1

OK, after a while of trying possible combinations I found a solution.

Activation function must be set after setting layer sizes. I dont know exactly why, but when I flip rows like this

nn->setLayerSizes(layers);
nn->setActivationFunction(cv::ml::ANN_MLP::SIGMOID_SYM);

its working. If someone knows the reason of this, please tell me.