Vector Newton Raphson Method coding help

4 views (last 30 days)
Kevin Tovson
Kevin Tovson on 1 Nov 2015
Answered: Nitin Khola on 3 Nov 2015
I have a code for the Vector Newton Raphson method (which solves 2 functions that are a function of both x and y) and I am getting the error 'Subscripted assignment dimension mismatch' at line 17 and 18. If anyone has any clue how to fix this problem to where my code runs smoothly I would really appreciate it!
x=15;
y=12;
v=[x;y];
tol=.01;
loopcnt=0;
Maxloop=56;
while loopcnt<Maxloop
f1t=-sind(x)-sind(x+y);
f1b=-sind(x+y);
f2t=cosd(x)+cosd(x+y);
f2b=cosd(x+y);
Jacobian=[f1t f1b;f2t f2b];
f1=cosd(x)+cosd(x+y)-1;
f2=sind(x)+sind(x+y)-1.1;
F=[f1;f2];
vNew=v-inv(Jacobian)*F;
vNew(1,1)=xNew
vNew(2,1)=yNew
xNew=x
yNew=y
if (vNew-vOld)>tol
else
break
end
loopcnt=loopcnt+1;
end
  1 Comment
Jan
Jan on 1 Nov 2015
Please do not let us guess, which one is the line 17 and 18. But, by the way, it is impossible that the line 18 stops with an error, if the code stops in line 17 already.
The code should stop in the line "vNew(1,1)=xNew" also due to an unknown variable "xNew".

Sign in to comment.

Answers (1)

Nitin Khola
Nitin Khola on 3 Nov 2015
For the community to help you better, please make sure you provide code that reproduces the issue. As Jan Simon pointed out, define xNew, vOld etc.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!