Cannot find solution when using fsolve

Hi all,

I am trying to solve the following nonlinear equations using fsolve:

basex=-60.0235;
basey=-7.0012;
options=optimset('Algorithm','levenberg-marquardt');
X=fsolve(@(x)[basex/sqrt(4*x(2)^2*x(1)^2+1)...
  -basey*2*x(2)*x(1)/sqrt(4*x(2)^2*x(1)^2+1)+x(1);...
  basex*2*x(2)*x(1)/sqrt(4*x(2)^2*x(1)^2+1)...
  +basey/sqrt(4*x(2)^2*x(1)^2+1)+x(1)^2*x(2)],[59;-0.001],options)

However, I was told no solution found. Acctually there should be a solution, because the basex and basey value is generated through the same set of equations:

x=[60;-0.002];
A=[1/sqrt(4*x(2)^2*x(1)^2+1) -2*x(2)*x(1)/sqrt(4*x(2)^2*x(1)^2+1) x(1);
  2*x(2)*x(1)/sqrt(4*x(2)^2*x(1)^2+1) 1/sqrt(4*x(2)^2*x(1)^2+1) x(1)^2*x(2);
  0 0 1];
B=[0;0;1];
Base=linsolve(A,B) % basex=Base(1),basey=Base(2)

Anyone can help me with this? Thanks a lot!

-Bay

Answer 1

[Star Strider]

You need to do element-wise operations using the dot (.) operator:

basex=-60.0235;
basey=-7.0012;
options=optimset('Algorithm','levenberg-marquardt');
X=fsolve(@(x)[basex./sqrt(4*x(2).^2.*x(1).^2+1)...
  -basey*2.*x(2).*x(1)./sqrt(4*x(2).^2.*x(1).^2+1)+x(1);...
  basex*2*x(2).*x(1)./sqrt(4*x(2).^2.*x(1).^2+1)...
  +basey./sqrt(4*x(2).^2.*x(1).^2+1)+x(1).^2.*x(2)],[59;-0.001],options)

X =
    35.1460e-006
    -4.9918e-003

See the documentation on: Array vs. Matrix Operations for details.