integrationtest.java

数值分析算法源码(java) 这个学期一边学习java一边学习数值分析,因此用java写了一个数值分析算法的软件包numericalAnalysis. [说明] 适合使用者:会java的

package numericalAnalysis.integration;

import java.util.Scanner;
import numericalAnalysis.function.Function;

public class IntegrationTest {// -------------注意!!!!!!被积函数f(x)在下面Function接口写入-----------------------------------------
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		Integration problem;
		MyFunction function;//被积函数
		String anotherChoice;// 新的积分方法
		String another;// 新建一个积分问题的判断

		System.out.println("\n----------------------------本程序求解积分问题"
				+ "----------------------------\n\n");

		do {
			//确认被积函数已经写入Function接口
			System.out.println("你要的被积函数若未在源码中写好则请先写好,若写好了请按c:\n");
			another=input.next();
			//输入积分区间左右端点
			System.out.println("请输入积分区间左端点:\n");
			double leftEndpoint = input.nextDouble();
			System.out.println("请输入积分区间右端点:\n");
			double rightEndpoint = input.nextDouble();
			function=new MyFunction();
			problem=new Integration(leftEndpoint,rightEndpoint,function);//新建这个定积分
			
			do {
				int choice = 0;
				boolean retry = true;
				while (retry) {
					retry = false;
					System.out.println();
					System.out.println("1---牛顿柯特斯公式求解积分");
					System.out.println("2---龙贝格法求解积分");
					System.out.println("3---复化牛顿柯特斯公式求解积分");
					System.out.println("请选择:");
					try {
						choice = Integer.parseInt(input.next());
					} catch (NumberFormatException e) {
						System.out.println("请别胡乱输入!\n");
						retry = true;
					}
				}

				switch (choice) {
				case 1:
					System.out.println("请输入牛顿柯特斯公式的n (0<n<8):");
					int n = input.nextInt();

					System.out.println();
					System.out.println("牛顿柯特斯公式求解积分结果:");
					System.out.println(problem.newtonCotes(n));
					break;
				case 2:
					System.out.println("请输入龙贝格积分的允许误差:");
					double errorAllowed = input.nextDouble();// 允许误差
					
					System.out.println();
					System.out.println("龙贝格法求解积分结果:");
					System.out.println(problem.romberg(errorAllowed));
					break;
				case 3:
					System.out.println("请输入大段数m:");
					int m = input.nextInt();
					System.out.println("请输入牛顿柯特斯公式的n (0<n<8):");
					n = input.nextInt();
					
					System.out.println();
					System.out.println("复化牛顿柯特斯公式求解积分结果:\nI=");
					System.out.println(problem.minuteNewtonCotes(m, n));
					break;
				}

				System.out.println("    要再使用其他积分方法(对于刚才这个定积分)吗?   y/n:");
				anotherChoice = input.next();

			} while (anotherChoice.equalsIgnoreCase("y"));

			System.out.println("\n         改变定积分区间左右端点?  y/n:");
			another = input.next();
		} while (another.equalsIgnoreCase("y"));
	}
	
	private static class MyFunction implements Function {
		// -------------注意!!!!!!被积函数f(x)在此写入-----------------------------------------
		public double f(double x) {
			return Math.sqrt(x);
		}
		
		public double f(double x, double y) {
			return 0;
		}
		
	}
}