翻译I'm trying to calculate the mahalanobis distance with c#. I can't find any real good examples online and I'm new to C#. I am especially having trouble getting the covariance matrix to run right. Any help would be appreciated. Thanks!
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using MathNet.Numerics.LinearAlgebra.Double; namespace MahalanobisDistance { class Program { static void Main(string[] args) { Program p = new Program(); DenseVector vector1 = new DenseVector(4); DenseVector vector2 = new DenseVector(4); DenseMatrix matrix1 = new DenseMatrix(vector1.Count/2); vector1[0] = 1; vector1[1] = 2; vector1[2] = 3; vector1[3] = 4; vector2[0] = 2; vector2[1] = 12; vector2[2] = 14; vector2[3] = 18; matrix1 = p.twoPassCovariance(vector1, vector2); for(int i = 0; i < matrix1.RowCount; i++) { for(int k = 0; k < matrix1.ColumnCount; k++) { Console.Write(matrix1[k, i] + " "); } //Mahalanobis2(v1, v2, covariance); Console.Write("\n"); } } public DenseMatrix twoPassCovariance(DenseVector data1, DenseVector data2) { int n = data1.Count; double mean1 = data1.Average(); double mean2 = data2.Average(); DenseMatrix covariance = new DenseMatrix(data1.Count); double x; for(int i = 0; i < 2; i++) { for (int k = 0; k < n; k++) { double a = data1[i] - mean1; double b = data2[k] - mean2; x = a*b; covariance[i, k] = x; } } covariance.Multiply(1/n); return covariance; } }}