皮尔逊相关系数-Java 学习之路

我编写了以下C＃代码来查找两个图像之间的Pearson相关系数 . 完整的源代码是here in the DotNetFiddle .

Correlation Source Code:

public sealed class PearsonCorrelation 
{
    public static double GetSimilarityScore(double[,] p, double[,] q)
    {
        int Width = p.GetLength(0);
        int Height = p.GetLength(1);

        if (Width != q.GetLength(0) || Height != q.GetLength(1))
        {
            throw new ArgumentException("Input vectors must be of the same dimension.");
        }

        double pSum = 0, qSum = 0, pSumSq = 0, qSumSq = 0, productSum = 0;
        double pValue, qValue;

        for (int y = 0; y < Height; y++)
        {
            for (int x = 0; x < Width; x++)
            {
                pValue = p[y, x];
                qValue = q[y, x];

                pSum += pValue;
                qSum += qValue;
                pSumSq += pValue * pValue;
                qSumSq += qValue * qValue;
                productSum += pValue * qValue;
            }
        }

        double numerator = productSum - ((pSum * qSum) / (double)Height);
        double denominator = Math.Sqrt((pSumSq - (pSum * pSum) / (double)Height) * (qSumSq - (qSum * qSum) / (double)Height));

        return (denominator == 0) ? 0 : numerator / denominator;
    }
}

Result:

enter image description here

相同的图片加载在两个图片框中 .

它们的相关系数的值已变为 -1 .

这是正确的结果吗？

如果不是，我该怎么做才能纠正它？

1 回答

相同序列的相关性必须为 1

似乎你在例程的最后有问题;代替

double numerator = productSum - ((pSum * qSum) / (double)Height);
 double denominator = Math.Sqrt((pSumSq - (pSum * pSum) / (double)Height) * (qSumSq - (qSum * qSum) / (double)Height));

你应该把

double n = ((double) Width) * Height;

 double numerator = productSum - ((pSum * qSum) / n);
 double denominator = 
   Math.Sqrt((pSumSq - (pSum * pSum) / n) * (qSumSq - (qSum * qSum) / n));

看到

https://en.wikipedia.org/wiki/Pearson_product-moment_correlation_coefficient

回复于 2024-05-14T19:25:55+08:00

皮尔逊相关系数

1 回答

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