PDF《《数学实验与 Matlab》程序》

);

disp('

[x,fval,exitflag,output] = fminunc({f,GRAD},x0,OPTIONS);

'

);

[x,fval,exitflag,output] = fminunc({f,GRAD},x0,OPTIONS);

hold off disp('

'

) disp('

Strike any key for menu'

) pause case

3 %当method= 3, 采用最速下降法.clf, xlabel('

x1'

),ylabel('

x2'

), title('

Minimization of the Banana function'

)

35 contour(xx,yy,meshd,conts) hold on plot(-1.9,2,'

ro'

), text(-1.9,2,'

Start Point'

) plot(1,1,'

ro'

), text(1,1,'

Solution'

) OPTIONS=optimset('

LargeScale'

,'

off'

);

OPTIONS = optimset(OPTIONS,'

gradobj'

,'

on'

);

OPTIONS=optimset(OPTIONS,'

HessUpdate'

,'

steepdesc'

);

%将HessUpdate属性设置为steepdesc就使fminunc指令采用最速下降法.GRAD=inline('

[100*(4*x(1)^3-4*x(1)*x(2))+2*x(1)-2;

… 100*(2*x(2)-2*x(1)^2);

banplot6_4(x)]'

);

f=inline('

100*(x(2)-x(1)^2)^2+(1-x(1))^2'

);

disp('

[x,fval,exitflag,output] = fminunc({f,GRAD},x0,OPTIONS);

'

);

[x,fval,exitflag,output] = fminunc({f,GRAD},x0,OPTIONS);

hold off disp('

'

) disp('

Strike any key for menu'

) pause case

4 %当method= 4, 采用单纯形方法.clf,hold on, xlabel('

x1'

),ylabel('

x2'

), title('

Minimization of the Banana function'

) contour(xx,yy,meshd,conts), plot(-1.9,2,'

ro'

), text(-1.9,2,'

Start Point'

) plot(1,1,'

ro'

), text(1,1,'

Solution'

) OPTIONS=optimset('

LargeScale'

,'

off'

);

OPTIONS = optimset(OPTIONS,'

gradobj'

,'

off'

........