Лабораторная работа: Градієнтні методи

f=3*x1-1.2*x2+exp (0.02*x1*x1+1.3*x2*x2);

return (f);

}

double df1 (double x1, double x2)

{double f1;

f1=3+0.04*x1*exp (0.02*x1*x1+1.3*x2*x2);

return (f1);

}

double df2 (double x1, double x2)

{double f2;

f2=-1.2+2.6*x2*exp (0.02*x1*x1+1.3*x2*x2);

return (f2);

}

double zsech (double a,double b,double x1k,double x2k,double z1,double z2)

{

double eps=0.0001;

double x1,x2,y1,y2,t;

t= (1+sqrt (5)) /2;

x1=a- (b-a) / (t);

y1=f (x1k-x1*z1,x2k-x1*z2);

x2=a+ (b-a) /t;

y2=f (x1k-x2*z1,x2k-x2*z2);

while ( (b-a) >eps) {

if (y1<=y2) { b=x2; x2=x1; y2=y1; x1=a+b-x2; y1=f (x1k-x1*z1,x2k-x1*z2); }

else { a=x1; x1=x2; y1=y2; x2=a+b-x1; y2=f (x1k-x2*z1,x2k-x2*z2); }

}

// if (y1<y2) b=x2;

// else a=x1;

return ( (a+b) /2);