LabAlgo/helper.cs at main · Saunders-Trinity/LabAlgo · GitHub

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//helper functions, maybe make a class for these?
using System;
public class helperFunctions {
    //may need helpers to calculate math stuff
public static double[] Zero(int n){
    return new double[n];//zero vector of lenth n
}

public static double[] Copy(double[] a ){
    double[] b = new double[a.Length];
    Array.Copy(a, b, a.Length);
    return b;
}
//adding
public static double[] Add(double[] a, double[] b)
{
    int n = a.Length;
    double[] c = new double[n];

    for (int i = 0; i < n; i++)
        c[i] = a[i] + b[i];

    return c;
}

//subtracting
public static double[] Sub(double[] a, double[] b)
    {
        int n = a.Length;
        double[] c = new double[n];

        for (int i = 0; i < n; i++)
            c[i] = a[i] - b[i];

        return c;
    }


public static double[] Scale(double[] a, double s)
    {
        int n = a.Length;
        double[] b = new double[n];

        for (int i = 0; i < n; i++)
            b[i] = s * a[i];

        return b;
    }


//finds eucliedean norm
public static double Norm(double[] a)
    {
        double sum = 0.0;

        for (int i = 0; i < a.Length; i++)
            sum += a[i] * a[i];

        return Math.Sqrt(sum);
    }

//dot product
public static double Dot(double[] a, double[] b)
    {
        double sum = 0.0;

        for (int i = 0; i < a.Length; i++)
            sum += a[i] * b[i];

        return sum;
    }


//clamping each element to min,max
public static double[] Clamp(double[] a, double min, double max)
    {
        int n = a.Length;
        double[] b = new double[n];

        for (int i = 0; i < n; i++)
        {
            if (a[i] < min) b[i] = min;
            else if (a[i] > max) b[i] = max;
            else b[i] = a[i];
        }

        return b;
    }


//gradient helper
public static double[] FiniteDifferenceGradient(
    Func<double[], double> f,
    double[] x,
    double eps = 1e-6)
{
    int n = x.Length;
    double[] grad = new double[n];
    double[] xPerturbed = helperFunctions.Copy(x);

    double f0 = f(x);

    for (int i = 0; i < n; i++)
    {
        xPerturbed[i] += eps;
        grad[i] = (f(xPerturbed) - f0) / eps;
        xPerturbed[i] = x[i];
    }

    return grad;
}


}