NNMath.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MathClasses
{
    public class NNMath
    {
        // method to compute sigmoid activation function
        public double Sigmoid(double x)
        {
            return 1.0 / (1.0 + Math.Exp(-1.0 * x));
        }

        // method to take sigmoid of every element of a vector (array)
        public double[] VectorSigmoid(double[] vec)
        {
            // find dimensions of vector
            int dim = vec.GetLength(0);

            // initialize output vector
            double[] output = new double[dim];

            // populate output vector
            for (int i = 0; i < dim; i++)
            {
                output[i] = Sigmoid(vec[i]);
            }
            return output;
        }
    }
}