机械优化设计实验c语言程序.doc

二次插值法 #include quot;stdio.hquot; #include quot;math.hquot; #include quot;conio.hquot; void main() { float *area(float a1,float p,float a[3]); float f(float x); float ar,fr; float a2,a3; float f1,f2,f3; float a1=10,p=0.01,e=0.00001; float pa[3]; area(a1,p,pa); a1=pa[0]; a2=pa[1]; a3=pa[2]; f1=f(a1); f2=f(a2); f3=f(a3); do { ar=((a3*a3-a2*a2)*f1+(a1*a1-a3*a3)*f2+(a2*a2-a1*a1)*f3); ar=ar/2/((a3-a2)*f1+(a1-a3)*f2+(a2-a1)*f3); fr=f(ar); if(argt;a2) {if(frgt;f2) {a3=ar;f3=fr;} else if(frlt;f2) {a1=a2;f1=f2; a2=ar;f2=fr;} else {a3=ar;a1=a2;a2=(a1+a3)/2; f1=f2;f3=fr;f2=f(a2);} } else if(arlt;a2) {if(frgt;f2) {a1=ar;f1=fr;} else if(frlt;f2) {a3=a2;f3=f2; a2=ar;f2=fr;} else {a1=ar;a3=a2;a2=(a1+a3)/2; f1=fr;f3=f2;f2=f(a2);} - 1 - } if(fabs(a1-a3)lt;=e) break; }while(1); if(f2lt;fr) {ar=a2;fr=f2;} printf(quot;\nx*=%f\nf(x*)=%fquot;,ar,fr); } float *area(float a1,float p,float a[3]) {float f(float x); float a2,f2,a3,f3,temp; float acc=0.01; float f1=f(a1); float p; while(1) {a2=a1+p;f2=f(a2); if(f2gt;=f1) {if(fabs(f2-f1)lt;acc) p=p/2; else p=-p; } else break; } while(1) {a3=a2+p;f3=f(a3); if(f2lt;=f3) break; p=2*p; a1=a2;f1=f2; a2=a3;f2=f3; } if(a1gt;a3) {temp=a1;a1=a3;a3=temp;} a[0]=a1;a[1]=a2;a[2]=a3; return a; } float f(float x) {float y=pow(x,4)-4*pow(x,3)-6*pow(x,2)-16*x+4; return y; } 变尺度法 计算 f(x1,x2)=x1+2*x2-4*x1-2*x1*x2 的无约束极值，初始点x0=[1,1]。 /* tt ---- 一维搜索初始步长 - 2 - ff ---- 差分法求梯度时的步长 ac ---- 终止迭代收敛精度 ad ---- 一维搜索收敛精度 n ----- 设计变量的维数 xk[n] -- 迭代初始点 */ #includelt;stdio.hgt; #includelt;stdlib.hgt; #includelt;math.hgt; #includelt;conio.hgt; #define tt 0.01 #define ff 1.0e-6 #define ac 1.0e-6 #define ad 1.0e-6 #define n 2 double ia; double fny(double *x) { double x1=x[0],x2=x[1]; double f; f=x1*x1+2*x2*x2-4*x1-2*x1*x2; return f; } double * iterate(double *x,double a,double *s) { double *x1; int i; x1=(double *)malloc(n*sizeof(double)); for(i=0;ilt;n;i++) x1[i]=x[i]+a*s[i]; return x1; } double func(double *x,double a,double *s) { double *x1; - 3 - double f;