传感与检测技术，Pt100热电阻测温实验报告，江南大学物联网

public class LeastSquares {
 public static void matching(double[] x, double[] y, double[] input, double fully) {
 double k = getK(x, y);
 double b = getB(x, y);
 System.out.println("线性回归系数 k 值：\t" + k + "\n" + "线性回归系数 b 值：\t" + 
b);
 double maxy = 0; //用来记录最大偏差
 //寻找最大偏差
 for (int i = 0; i < input.length; i++) {
 if (Math.abs(k * input[i] + b - y[i]) > maxy){
 maxy = Math.abs(k * input[i] + b - y[i]);
 }
 }
 System.out.println("最大偏差为：" + maxy);
 //求灵敏度
 double s = 0;
 double sum = 0;
 for (int i = 1; i < y.length; i++) {
 sum += y[i] - y[i-1];
 }
 s = sum / (y.length - 1) / 20;
 System.out.println("灵敏度为：" + Math.abs(s));
 //求非线性误差
 System.out.println("非线性误差为：" + Math.abs(maxy/fully*100) + "%");
 }
 //返回 x 的系数 k 公式：k = (n sum( xy ) - sum( x ) sum( y )) / (n sum( x^2 )-sum(x) ^ 2)
 public static double getK(double[] x, double[] y) {
 int n = x.length;
 return (double) ((n * pSum(x, y) - sum(x) * sum(y)) / (n * sqSum(x) - Math.pow(sum(x), 
2)));
 }
 //返回常量系数系数 b 公式：b = sum( y ) / n - k * sum( x ) / n
 public static double getB(double[] x, double[] y) {
 int n = x.length;
 double k = getK(x, y);
 return sum(y) / n - k * sum(x) / n;
 }
 //求和
 private static double sum(double[] ds) {
 double s = 0;
 for (double d : ds)
 {
 s = s + d;
 }
 return s;
 }
 //求平方和
 private static double sqSum(double[] ds) {
 double s = 0;
 for (double d : ds) {
 s = (double) (s + Math.pow(d, 2));
 }
 return s;
 }
 //返回对应项相乘后的和
 private static double pSum(double[] x, double[] y) {
 double s = 0;
 for (int i = 0; i < x.length; i++) {
 s = s + x[i] * y[i];
 }
 return s;
 }
 public static void main(String[] args) {
 double[] x1 = {52.5,55,60,65,70,75,80,85,90,95,100};
 double[] y1 = {0,-0.54,-1.46,-2.32,-3.20,-4.06,-4.90,-5.72,-6.51,-7.31,-8.01};
 double[] inputs1 = x1;
 System.out.println("Pt100 热电阻测温实验拟合直线：");
 matching(x1, y1,inputs1,y1[y1.length-1]);
 }
}