bool sigmoid;// to know if sigmoid checkbox is checked or tanh
        public BackProbagation(double threshould, double a, double learning_rate, bool sigmoid, string Single_file_Path)
        {
            //digits = new DigitDataFill();
            if (!DigitDataFill.With_Pca)
            {
                DigitDataFill.Fill_Training_data();
                DigitDataFill.Fill_Testing_data();

                if (Single_file_Path != "!")// if browser button is clicked
                {
                    DigitDataFill.fill_single_file(Single_file_Path);
                }
            }
            this.learning_rate = learning_rate;
            this.threshould    = threshould;
            this.a             = a;
            this.sigmoid       = sigmoid;
        }
 public static void read_data()
 {
     DigitDataFill.init();
     DigitDataFill.Fill_Training_data();
     DigitDataFill.Fill_Testing_data();
 }