Java写的数值分析中的一些程序

import java.util.Arrays; public class BisectionMethod { public static double result; public static void dirivation(double a[], double b[]){ int n = a.length; for(int i = 0; i < a.length - 1; i++){ b[i] = a[i] * (n - 1 - i); } } public static double polynomial(double a[], double x1){ double sum1 = 0; for(int i = 0; i < a.length; i++){ double mul1 = 1; for(int j = 0; j < a.length - 1 - i; j++){ mul1 *= x1; } sum1 += a[i] * mul1; } return sum1; } public static void bisection(double a[], double x1, double x2, int count){ if(count == 0){ result = (x1 + x2) / 2; return ; } double sum = 0; double sum1 = 0; for(int i = 0; i < a.length; i++){ double mul = 1; double mul1 = 1; for(int j = 0; j < a.length - 1 - i; j++){ mul *= (x1 + x2) / 2; mul1 *= x1; } sum += a[i] * mul; sum1 += a[i] * mul1; } System.out.println(count + "::::" + (x1 + x2) / 2); if(sum == 0){ result = (x1 + x2) / 2; return ; } else if(sum * sum1 < 0){ bisection(a, x1, (x1 + x2) / 2, count - 1); } else { bisection(a, (x1 + x2) / 2, x2, count - 1); } } public static void regularFalsi(double a[], double x1, double x2, int count){ if(count == 0){ result = x2 - (polynomial(a, x2) * (x2 - x1)) / (polynomial(a, x2) - polynomial(a, x1)); return ; } double sum = 0; double sum1 = 0; for(int i = 0; i < a.length; i++){ double mul = 1; double mul1 = 1; for(int j = 0; j < a.length - 1 - i; j++){ mul *= x2 - (polynomial(a, x2) * (x2 - x1)) / (polynomial(a, x2) - polynomial(a, x1)); mul1 *= x1; } sum += a[i] * mul; sum1 += a[i] * mul1; } System.out.println(count + "::::" + (x2 - (polynomial(a, x2) * (x2 - x1)) / (polynomial(a, x2) - polynomial(a, x1)))); if(sum == 0){ result = x2 - (polynomial(a, x2) * (x2 - x1)) / (polynomial(a, x2) - polynomial(a, x1)); return ; } else if(sum * sum1 < 0){ regularFalsi(a, x1, x2 - (polynomial(a, x2) * (x2 - x1)) / (polynomial(a, x2) - polynomial(a, x1)), count - 1); } else { regularFalsi(a, x2 - (polynomial(a, x2) * (x2 - x1)) / (polynomial(a, x2) - polynomial(a, x1)), x2, count - 1); } } public static void staticIterator(double a[], double x, int count){ for(int i = 0; i < count; i++){ System.out.println(i + "::::" + x); x = (-1) * (Math.sqrt(Math.exp(x) / 3)); } } public static void newtonIterator(double a[], double x, int count, int m){ int n = a.length; double b[] = new double[a.length - 1]; for(int i = 0; i < a.length - 1; i++){ b[i] = a[i] * (n - 1 - i); } //System.out.println(Arrays.toString(b)); System.out.println("**************Newton1*****************"); for(int i = 0; i < count; i++){ System.out.println(i + "::::" + x); x = x - (polynomial(a, x)) / (polynomial(b, x)); } System.out.println("**************Newton2*****************"); for(int i = 0; i < count; i++){ System.out.println(i + "::::" + x); x = x - m * (polynomial(a, x)) / (polynomial(b, x)); } System.out.println("**************Newton3*****************"); double[] c = new double[b.length - 1]; dirivation(b, c); for(int i = 0; i < count; i++){ System.out.println(i + "::::" + x); x = x - ((polynomial(a, x)) * (polynomial(b, x))) / (polynomial(b, x) * polynomial(b, x) - polynomial(a, x) * polynomial(c, x)); } } public static void newtonAppli(double a[], double x, int count){ for(int i = 0; i < count; i++){ System.out.println(i + "::::" + x); x = (x + 3 / x) / 2; } } public static void secant(double a[], double x1, double x2, int count){ double fp = Math.cos(x1) - x1; double fr = Math.cos(x2) - x2; double x = 0; System.out.println(0 + "::::" + x1); //System.out.println(1 + "::::" + x2); for(int i = 1; i < count; i++){ System.out.println(i + "::::" + x2); x = x2; x2 = x2 - (fr * (x2 - x1)) / (fr -fp); x1 = x; fp = Math.cos(x1) - x1; fr = Math.cos(x2) - x2; } } public static void equationSet(double x1, double x2, int count){ double tx1 = x1; double tx2 = x2; //System.out.println(1 + "::::" + x2); /*for(int i = 1; i < count; i++){ System.out.println(i + "::::(" + x1 + " , " + x2 + ")"); x1 = (tx1 * tx1 + tx2 * tx2 + 8) / 10; x2 = (tx1 * tx2 * tx2 + tx1 + 8) / 10; tx1 = x1; tx2 = x2; }*/ for(int i = 1; i < count; i++){ System.out.println(i + "::::(" + x1 + " , " + x2 + ")"); x1 = (x1 * x1 + x2 * x2 + 8) / 10; x2 = (x1 * x2 * x2 + x1 + 8) / 10; } } public static void main(String args[]){ double[] a = {1, 0, -4, 0, 4}; //bisection(a, 5, 10, 30); //regularFalsi(a, 5, 10, 3); //staticIterator(a, 14322, 28); //newtonIterator(a, 1.5, 10, 2); /*System.out.println("**************Newton3*****************"); newtonAppli(a, 1, 7); System.out.println("**************Newton3*****************"); newtonAppli(a, 3, 7); System.out.println("**************Newton3*****************"); newtonAppli(a, 10, 7);*/ //secant(a, 0.5, 0.78539816, 6); equationSet(0.8, 0.8, 10); System.out.println(result); } }