main_loop.cpp

int main(int argc, const char * argv[]) {    
    for (unsigned i = 0; i != 10000; ++i) {        
        vector<float> layer_1 = sigmoid(dot(X, W0, 4, 2, 4 ) );
        vector<float> layer_2 = sigmoid(dot(layer_1, W1, 4, 4, 1 ) );        
        vector<float> layer_2_delta = (y - layer_2) * sigmoid_d(layer_2);
        vector<float> layer_1_delta = dot(layer_2_delta, transpose( &W1[0], 4, 1 ), 4, 1, 4) * sigmoid_d(layer_1);        
        W1 = W1 + dot(transpose( &layer_1[0], 4, 4 ), layer_2_delta, 4, 4, 1);
        W0 = W0 + dot(transpose( &X[0], 4, 2 ), layer_1_delta, 2, 4, 4);
    };
    return 0;
}