MATLAB牛顿法源代码

1、fun cti on homP,iter,err=newto n('f,'JF',7.8e-001;4.9e-001;3.7e-001,0.01,0.001,1000);disp(P);disp(iter);disp(err);fun cti on Y=f(x,y,z)Y=xA2+yA2+zA2-1;2*xA2+yA2-4*z;3*xA2-4*y+zA2;fun cti on y=JF(x,y,z)f1='xA2+yA2+zA2-1'f2='2*xA2+yA2-4*z'f3='3*xA2-4*y+zA2'df1x=diff

2、(sym(f1),'x');df1y=diff(sym(f1),'y');df1z=diff(sym(f1),'z');df2x=diff(sym(f2),'x');df2y=djff(sym(f2),'y');df2z二diff(sym(f2),'z');df3x=diff(sym(f3),'x');df3y=djff(sym(f3),'y');df3z=djff(sym(f3),'z');j=df1x,df1y,df1z;df2x,df2y,df2

3、z;df3x,df3y,df3z; y=(j);function P,iter,err=newton(F,JF,P,tolp,tolfp,max)漏入P为初始猜测值，输出P则为近似解%JF为相应的Jacobian矩阵%tolp为P的允许误差%tolfp为f(P)的允许误差%max循环次数Y=f(F,P(1),P(2),P(3);for k=1:maxJ=f(JF,P(1),P(2),P(3);Q=P-i nv(J)*Y;Z=f(巳Q(1),Q(2),Q(3);err=no rm(Q-P);P=Q;Y二Z;iter=k;if (err<tolp)|(abs( Y)<tolfp|abs

4、( Y)<0.0001)breakendend<pre Ian g="matlab" lin e="1" file="test.m"> fun cti on homework4P,iter,err=newto n('f,'JF',7.8e-001;4.9e-001;3.7e-001,0.01,0.001,1000);disp(P);disp(iter);disp(err);fun cti on Y=f(x,y,z)Y=xA2+yA2+zA2-1;2*xA2+yA2-4*z;3*xA2-4*y+

5、zA2;fun cti on y=JF(x,y,z)f1='xA2+yA2+zA2-1'f2='2*xA2+yA2-4*z'f3='3*xA2-4*y+zA2'dflx二diff(sym(f1),'x');dfly二diff(sym(f1),'y');df1z=djff(sym(f1),'z');df2x=diff(sym(f2),'x');df2y=diff(sym(f2),'y');df2z=diff(sym(f2),'z');df3x=diff(

6、sym(f3),'x');df3y=djff(sym(f3),'y');df3z=diff(sym(f3),'z');j二df1x,df1y,df1z;df2x,df2y,df2z;df3x,df3y,df3z;y=(j);function P,iter,err=newton(F,JF,P,tolp,tolfp,max)漏入P为初始猜测值，输出P则为近似解%JF为相应的Jacobian矩阵%tolp为P的允许误差%tolfp为f(P)的允许误差%max循环次数Y=f(F,P(1),P(2),P(3);for k=1:maxJ=f(JF,P(1),P (2),P(3);Q=P-i nv(J)*Y;Z=f(F,Q(1),Q (2) ,