java实现最小二乘法(附完整源码)

以下是Java实现最小二乘法的完整源码，供参考：

public class LeastSquares {
    public static void main(String[] args) {
        double[] x = {1, 2, 3, 4, 5};
        double[] y = {1, 3, 5, 7, 9};
        double[] result = leastSquares(x, y);

        System.out.println("y = " + result[0] + "x + " + result[1]);
    }

    public static double[] leastSquares(double[] x, double[] y) {
        int n = x.length; // 样本数
        double sumX = 0.0; // x的和
        double sumY = 0.0; // y的和
        double sumXY = 0.0; // x*y的和
        double sumXX = 0.0; // x^2的和

        // 计算x、y、xy、xx的和
        for (int i = 0; i < n; i++) {
            sumX += x[i];
            sumY += y[i];
            sumXY += x[i] * y[i];
            sumXX += x[i] * x[i];
        }

        // 计算斜率k和截距b
        double k = (n * sumXY - sumX * sumY) / (n * sumXX - sumX * sumX);
        double b = (sumY - k * sumX) / n;

        double[] result = {k, b};
        return result;
    }
}

该代码实现了最小二乘法的算法，接收两个数组x和y作为输入，计算线性回归方程的斜率k和截距b，最后输出结果。