package?com.li.jisuanfangfa;

import?java.io.*;
import?java.math.BigDecimal;

public?class?Adams?{

	public?static?void?main（String[]?args）?{
		double?x0?=?0;
		double?y0?=?1;
		double?h?=?0.1;
		int?N?=?10;

		File?fileSave?=?new?File（“E:\\Adams\\fileSave.txt“）;

		Adams.Adams（x0?y0?h?N?fileSave）;
	}

	public?static?void?Adams（double?x0?double?y0?double?h?int?N
			File?fileSave）?{
		//?使用經(jīng)典格式提供y1y2y3
		double?X[]?=?new?double[4];
		double?Y[]?=?new?double[4];
		X[0]?=?x0;
		Y[0]?=?y0;
		for?（int?i?=?1;?i?			X[i]?=?X[i?-?1]?+?h;
			double?k1?=?dfxADAMS（X[i?-?1]?Y[i?-?1]）;
			double?k2?=?dfxADAMS（X[i?-?1]?+?h?/?2?Y[i?-?1]?+?（h?/?2）?*?k1）;
			double?k3?=?dfxADAMS（X[i?-?1]?+?h?/?2?Y[i?-?1]?+?（h?/?2）?*?k2）;
			double?k4?=?dfxADAMS（X[i]?Y[i?-?1]?+?h?*?k3）;
			Y[i]?=?Y[i?-?1]?+?（h?/?6）?*?（k1?+?2?*?k2?+?2?*?k3?+?k4）;
		}

		//?亞當姆斯預(yù)報-校正系統(tǒng)
		int?n?=?4;
		double?x[]?=?new?double[N?+?1];
		double?y[]?=?new?double[N?+?1];
		double?yy[]?=?new?double[N?+?1];
		double?yp[]?=?new?double[N?+?1];
		for?（int?i?=?0;?i?			x[i]?=?X[i];
			y[i]?=?Y[i];
			yy[i]?=?0;
			yp[i]?=?dfxADAMS（x[i]?y[i]）;
		}
		while?（n?<=?N）?{
			x[n]?=?x[n?-?1]?+?h;
			yy[n]?=?y[n?-?1]
					+?（h?/?24）
					*?（55?*?yp[n?-?1]?-?59?*?yp[n?-?2]?+?37?*?yp[n?-?3]?-?9?*?yp[n?-?4]）;
			y[n]?=?y[n?-?1]
					+?（h?/?24）
					*?（9?*?dfxADAMS（x[n]?yy[n]）?+?19?*?yp[n?-?1]?-?5
							*?yp[n?-?2]?+?yp[n?-?3]）;
			yp[n]?=?dfxADAMS（x[n]?y[n]）;
			n++;
		}

		//?輸出結(jié)果
		BufferedWriter?writer?=?null;
		try?{
			writer?=?new?BufferedWriter（new?OutputStreamWriter（
					new?FileOutputStream（fileSave）））;
			for?（int?i?=?0;?i?<=?N;?i++）?{
				if?（i?					writer.write（approximate（x[i]?6）?+?“\t\t\t“
							+?approximate（y[i]?6））;
				}?else?{
					writer.write（approximate（x[i]?6）?+?“\t“
							+?approximate（yy[i]?6）?+?“\t“
							+?approximate（y[i]?6））;
				}
				writer.newLine（）;
			}
		}?catch?（Exception?e）?{
			System.out.println（“輸出文件失?。　埃?
			System.out.println（e）;
		}?finally?{
			try?{
				writer.close（）;
			}?catch?（Exception?e）?{

				System.out.println（e）;
			}
		}
	}

	private?static?double?approximate（double?x?int?scale）?{
		if?（scale?<=?0）?{
			throw?new?IllegalArgumentException（“非法參數(shù)：保留位數(shù)須大于0!“）;
		}
		BigDecimal?b?=?new?BigDecimal（x）;
		BigDecimal?one?=?new?BigDecimal（1）;
		return?b.divide（one?scale?BigDecimal.ROUND_HALF_UP）.doubleValue（）;
	}

	private?static?double?dfxADAMS（double?x?double?y）?{
		if?（y?!=?0）?{
			return?y?-?2?*?x?/?y;
		}?else?{
			return?Double.NaN;
		}
	}
}

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2013-12-28?20:21??計算方法\
?????目錄???????????0??2013-12-28?20:21??計算方法\JSfangfa\
?????文件?????????301??2013-12-16?19:00??計算方法\JSfangfa\.classpath
?????文件?????????384??2013-12-16?19:00??計算方法\JSfangfa\.project
?????目錄???????????0??2013-12-28?20:21??計算方法\JSfangfa\.settings\
?????文件?????????598??2013-12-16?19:00??計算方法\JSfangfa\.settings\org.eclipse.jdt.core.prefs
?????目錄???????????0??2013-12-28?20:21??計算方法\JSfangfa\bin\
?????目錄???????????0??2013-12-28?20:21??計算方法\JSfangfa\bin\com\
?????目錄???????????0??2013-12-28?20:21??計算方法\JSfangfa\bin\com\li\
?????目錄???????????0??2013-12-28?20:21??計算方法\JSfangfa\bin\com\li\jisuanfangfa\
?????文件????????3817??2013-12-24?16:40??計算方法\JSfangfa\bin\com\li\jisuanfangfa\Adams.class
?????文件????????3663??2013-12-23?18:19??計算方法\JSfangfa\bin\com\li\jisuanfangfa\Duri_Ritter.class
?????文件????????4186??2013-12-24?11:53??計算方法\JSfangfa\bin\com\li\jisuanfangfa\GossSeidel.class
?????文件????????3823??2013-12-28?00:17??計算方法\JSfangfa\bin\com\li\jisuanfangfa\LU.class
?????文件????????1162??2013-12-23?20:31??計算方法\JSfangfa\bin\com\li\jisuanfangfa\Newton.class
?????文件????????3287??2013-12-24?14:15??計算方法\JSfangfa\bin\com\li\jisuanfangfa\Romberg.class
?????文件????????7502??2013-12-28?00:22??計算方法\JSfangfa\bin\com\li\jisuanfangfa\SplineFunction.class
?????文件????????4199??2013-12-27?21:10??計算方法\JSfangfa\bin\com\li\jisuanfangfa\TheLeastSquareMethod.class
?????文件????????2858??2013-12-24?15:26??計算方法\JSfangfa\bin\com\li\jisuanfangfa\Tools.class
?????文件?????????825??2013-12-28?00:25??計算方法\JSfangfa\bin\com\li\jisuanfangfa\ViewPanel$1.class
?????文件???????15964??2013-12-28?00:25??計算方法\JSfangfa\bin\com\li\jisuanfangfa\ViewPanel.class
?????文件?????????182??2013-12-28?00:03??計算方法\JSfangfa\fileSave.txt
?????目錄???????????0??2013-12-28?20:21??計算方法\JSfangfa\src\
?????目錄???????????0??2013-12-28?20:21??計算方法\JSfangfa\src\com\
?????目錄???????????0??2013-12-28?20:21??計算方法\JSfangfa\src\com\li\
?????目錄???????????0??2013-12-28?20:21??計算方法\JSfangfa\src\com\li\jisuanfangfa\
?????文件????????2666??2013-12-24?16:40??計算方法\JSfangfa\src\com\li\jisuanfangfa\Adams.java
?????文件????????2730??2013-12-23?13:18??計算方法\JSfangfa\src\com\li\jisuanfangfa\Duri_Ritter.java
?????文件????????3606??2013-12-24?11:53??計算方法\JSfangfa\src\com\li\jisuanfangfa\GossSeidel.java
?????文件????????3108??2013-12-28?00:17??計算方法\JSfangfa\src\com\li\jisuanfangfa\LU.java
?????文件????????1157??2013-12-23?20:31??計算方法\JSfangfa\src\com\li\jisuanfangfa\Newton.java
............此處省略34個文件信息