共轭梯度法程序源代码.doc

共轭梯度法程序源代码#include#include#define N 10#define eps pow(10,-6)double f(double x,double p,double t)double s;s=pow(x0+t*p0,2)+25*pow(x1+t*p1,2);return 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 t0,t1,t,h,alpha,f0,f1;int k=0;t0=2.5; /*初始值*/h=1; /*初始步长*/alpha=2; /*加步系数*/f0=f(x,p,t0);t1=t0+h;f1=f(x,p,t1);while(1) if(f1f0) h=alpha*h; t=t0; t0=t1; f0=f1; k+; else if(k=0) h=-h;t=t1; else *a=tt1?t:t1; break; t1=t0+h; f1=f(x,p,t1);/*以下是黄金分割法程序源代码*/double hjfg(double x,double p)double beta,t1,t2,t;double f1,f2;double 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*/printf(nx1=%lf,x2=%lf,p1=%lf,p2=%lf,x0,x1,p0,p1);printf(na,b=%lf,%lf,a,b);beta=(sqrt(5)-1.0)/2;t2=a+beta*(b-a); f2=f(x,p,t2);t1=a+b-t2; f1=f(x,p,t1);while(1) if(fabs(t1-t2)eps) break; else if(f1f2) t=(t1+t2)/2; b=t2; t2=t1; f2=f1; t1=a+b-t2; f1=f(x,p,t1); else a=t1; t1=t2; f1=f2; t2=a+beta*(b-a); f2=f(x,p,t2); t=(t1+t2)/2;return t;/*以下是共轭梯度法程序源代码*/void gtd()double xN,gN,pN,t=0,f0,mod1=0,mod2=0,nanda=0;int i,k,n;printf(请输入函数的元数值n=);scanf(%d,&n);printf(n请输入初始值:n);for(i=0;ieps) p0=-g0; p1=-g1; k=0; while(1) t=hjfg(x,p);/*调用黄金分割法求t的值*/ printf(np1=%lf,p2=%lf,t=%lf,p0,p1,t); x0=x0+t*p0; x1=x1+t*p1; g0=2*x0; g1=50*x1; /*printf(nx1=%lf,x2=%lf,g1=%lf,g2=%lf,x0,x1,g0,g1);*/ mod2=sqrt(pow(g0,2)+pow(g1,2); /*求梯度的长度*/ if(mod2=eps) break; else if(k+1=n) g0=2*x0; g1=50*x1; p0=-g0; p1=-g1; k=0; else nanda=pow(mod2,2)/pow(mod1,2); printf(nnanda=%lf,mod=%lf,nanda,mod2); p0=-g0+nanda*p0; p1=-g1+nanda*p1; mod1=mod2; k+; printf(n-); printf(n最优解为x1=%lf,x2=%lf,x0,x1);printf(n最终的函数值为%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:2 2x1=2.000000,x2=2.000000,p1=-4.000000,p2=-100.000000a,b=-4.500000,1.500000p1=-4.000000,p2=-100.000000,t=0.020030nanda=0.001474,mod=3.842730-x1=1.919879,x2=-0.003022,p1=-3.845655,p2=0.003665a,b=-4.500000,1.500000p1=-3.845655,p2=0.003665,t=0.499240-x1=-0.000026,x2=-0.001192,p1=0.000052,p2=0.059610a,b=-4.500000,1.500000p1=0.000052,p2=0.059610,t=0.020000nanda=0.000000,mod=0.000050-x1=-0.000025,x2=-0.000000,p1=0.000050,p2=0.000001a,b=-4.500000,1.500000p1=0.000050,p2=0.000001,t=0.495505-x1=-0.000000,x2=0.000000,p1=0.000000,p2=-0.000023a,b=-4.500000,