机械优化设计编程(C语言).doc

反反复复二分法：#include#includemath.h#define E 0.01void main() float a,b,x,erfen(float a,float b); printf(Enter a,bn); scanf(%f,%f,&a,&b); x=erfen(a,b); printf(x=%fn,x); float erfen(float a,float b) float c,df(float x); while (fabs(a-b)E) c=(a+b)/2; if(df(c)=0) break; else if(df(a)*df(c)0) b=c; else a=c; return c; float df(float x)return 2*x-6;黄金分割法：#include#includemath.h#define E 0.001#define H 0.618void main() float a,b,x; float goldcut(float a,float b); printf(Enter a,bn); scanf(%f,%f,&a,&b); x=goldcut(a,b); printf(x*=%fn,x); float goldcut(float a,float b) float x1,x2,y1,y2; float f(float x); x2=a+H*(b-a); x1=a+b-x2; y1=f(x1); y2=f(x2); while(fabs(y1-y2)=E) if(y1y2) a=x1; x1=x2; y1=y2; x2=a+H*(b-a); y2=f(x2); else b=x2; x2=x1; y2=y1; x1=a+(1-H)*(b-a); y1=f(x1); return (x1+x2)/2; float f(float x) return x*x-6*x+2;进退法：#include#includemath.hvoid main() float x0,h,x1,jintui(float x0, float h); printf(Enter x0,h:n); scanf(%f,%f,&x0,&h); x1=jintui(x0, h); printf(%f,%f)n,x0,x1);float jintui(float x0,float h) float f(float x),x1,march(float x0,float h); if(f(x0)f(x0+h) x1=march(x0,h); else h=-h; x1=march(x0,h); return x1; float f(float x) return x*x-6*x+2; float march(float x0,float h) float x1=x0+h; while(f(x0)f(x1) x0=x1; h=2*h; x1=x0+h; return x1; 牛顿法：#include#includemath.h#define E 0.0001void main() float x,x0,f(float x); float newton(float x); printf(Enter xn); scanf(%f,&x); x0=newton(x); printf(%f,%f)n,x0,f(x0);float newton(float x) float x1; float f(float x),df(float x),ddf(float x); while (fabs(df(x)E) x1=x-df(x)/ddf(x); x=x1; return x; float f(float x) return x*x-6*x+2; float df(float x) return 2*x-6; float ddf(float x) return 0*x+2;进退法与二分法结合：#include#includemath.h#define E 0.001void main() float x0,h,x1,x2; float jintui(float x0,float h); float erfen(float x0,float x1); printf(Enter x0,hn); scanf(%f,%f,&x0,&h);x1=jintui(x0,h); printf(%f,%f)n,x0,x1);x2=erfen(x0,x1); printf(%fn,x2);float jintui(float x0,float h)float x1;float f(float x);float march(float x0,float h);if(f(x0)f(x0+h) x1=march(x0,h);else h=-h; x1=march(x0,h); return x1;float f(float x) return x*x-6*x+2;float march(float x0,float h) float x1=x0+h;while(f(x0)f(x1) x0=x1; h=2*h; x1=x0+h; return x1;float erfen(float x0,float x1)float c,df(float x);while(fabs(x0-x1)E) c=(x0+x1)/2; if(df(c)=0) break; else if(df(x0)*df(c)0) x1=c; else x0=c; return c;float df(float x)return 2*x-6;进退与黄金法结合：#include#includemath.h#define H 0.618#define E 0.001void main() float x0,h,a,b,x1,x2; float jintui(float x0,float h); float goldcut(float a,float b); printf(Enter x0,hn); scanf(%f,%f,&x0,&h);x1=jintui(x0,h); printf(%f,%f)n,x0,x1);x2=goldcut(x0,x1); printf(x2*=%fn,x2); float jintui(float x0,float h) float x1,f(float x),march(float x0,float h); if(f(x0)f(x0+h) x1=march(x0,h); else h=-h;x1=march(x0,h); return x1;float march(float x0,float h) float x1=x0+h; while(f(x0)f(x1) x0=x1; h=2*h; x1=x0+h; return x1; float goldcut(float a,float b) float x1,x2,y1,y2; float f(float x); x2=a+H*(b-a); x1=a+b-x2; y1=f(x1); y2=f(x2); while(fabs(y1-y2)=E