共轭梯度法程序源代码

1、共扼梯度法程序源代码#include#iiiclude#define N 10#define eps pow( 10.-6)double f(double x,double p,double t)double s;s=pow(x0+t*p 0 ,2)+2 5 *pow(x 1 +t*p 1 ,2);leturn s;/*以下是进退法搜索区间源程序*/void sb(double *a,double *b.double x,double p)double tO,tl,t,h,alpha,ft),fl；mt k=0;t0=2.5;/* 初始值 */h=l；/*初始步长*/alpha=2;/*加步系

2、数*/fO=f(x,ptO);tl=tO+h;fl=f(x,p,tl);wlule(l)(h=alpha*h; t=tO;tO=tl;fO=f 1;k+;)else(if(k=0)h=-h;t=tl;elsebreak;)tl=tO+h;fl=Rx,p,tl);/*以下是黄金分割法程序源代码可double lijfg(double x.double p)double beta,tl,t2,t;doubledouble a=0,b=0;double *c,*d;c=&a,d=&b;sb(c,d,x,p);/*调用进退法搜索区间*/pnntf(”nxl=%lf.x2=%lf.pl=%lf,p2=%

3、lT,x0,xl,p0,pl);printf(na,b=%lf,%lf”,a,b);beta=(sqrt(5)-l .0)/2;t2=a+beta*(b-a); f2=f(x.p,t2);tl =a+b-t2;fl =Rx,p,t 1);wlule(l)if(fabs(tl-t2)eps)break;elset=(tl+t2)/2;b=t2; t2=tl;f2=fl; tl=a+b-t2;elsea=tl; tl=t2;fl =2t2=a+beta*(b-a);f2=f(x,p、t2);)t=(tl+t2)/2;return t;/*以卜是共粒梯度法程序源代码*/void gtd() doub

4、le xN.gN.pNj=0.fD,modl=0,mod2=0aianda=0; mt i,k.n;pnntf(”请输入函数的元数值n=);scanf(”d”,&n);pnntf(”n请输入初始值:n”)；foi(i=O;ieps)pO=-gO；pl=-gl；k=O;while(l)(t=hjfg(x,p);/*调用黄金分割法求t的值*/pnntfCnpl=%lf；p2=%lft=%lfp0,pl,t);xO=xO+t*pO; xl=xl+t*pl;g0=2*x0;gl=5O*xl；/*printfl,uxl=%lf,x2=%lf,gl=%lf,g2=%lf,x0,xl,g0,gl);*/mo

5、d2=sqit(pow(g 0 ,2 )+pow(gl,2); /* 求梯度的长度 */if(mod2=eps) break;else(if(k+l=n)(g0=2*x0; gl=50*xl；pO=-gO；pl=-gl；k=O;else(nanda=pow(mod2,2)/pow(mod 1,2);piiiitfi(n,iinanda=%lmod=%lfnandajiiod2);pO=-gO+nanda*pO;Pl=-gl+nanda*pl;modl=mod2;k+;i)pnntfCn”)；)printfCNn 最优解为 x 1=%lf x2=%lf x0,x 1 );pnntf(n 最终的函

6、数值为lf，,f(x,g,t);main()gtd()；运行结果如下：请输入函数的元数值n=2请输入初始值：22xl=2.000000,x2=2.000000.pI=4000000,p2=100.000000a,b=-4.500000,1.500000pl=4000000,p2=100.000000.t=0.020030nanda=0.001474jnod=3.842730 xl=L919879,x2=-0.003022,pl=3.845655,p2=0.003665a,b=-4.500000,1.500000pl=3.845655,p2=0.003665,t=0.499240 xl=0.000026,x2=-0.001192,pl=0.000052,p2=0.059610a,b=-4.500000,1.500000pl=0.000052,p2=0.059610.t=0.020000nanda=0.000000jnod=0.000050 xl=0.000025,x2=-0.000000.pl=0.000050,p2=0.000001a,b=-4.500000,1.500000pl=0.000050,p2=0.000001.t=0.495505 xl=0.000000,x2=0.000000,pl=0.000000,p2=-0.000023a,b=-4.500000,1.