Nonlinear Equation Solve

[Thomas D. Dean]

I have a set of 15 nonlinear equations in 15 unknowns.
The equations are large, 3000 characters per equation, maybe 100 terms 
and of the form  a1*(x1*x2*...*x14) + b1*(x1*x2* + ... + *x13*x15) + ...

The equations were generated by NEC4 and Maple for modeling an antenna.

The function eqnsetf is 55 lines, 144000 characters.  The top of the 
function extracts the values of y into the proper values.  eqnsetf(y) 
returns a reasonable looking vector.

I tried

> size(y)
  1 15
> [x, fval, info] =
   fsolve (@eqnsetf,y',optimset("TolX",1e-20,"TolFun",1e-20));
> info
info = 0

If I reduce the tol's, fsolve does not reach a solution.

> [x, fval, info] =
    fminunc (@eqnsetf,y',
             optimset("TolX",1e18,"TolFun",1e18,"ComplexEqn","on"));
error: __doglegm__: operator \: nonconformant arguments (op1 is 15x15, 
op2 is 225x1)
error: called from:
error:   /usr/local/share/octave/3.4.3/m/optimization/fminunc.m at line 
386, column 3
error:   /usr/local/share/octave/3.4.3/m/optimization/fminunc.m at line 
233, column 9

Any ideas?

Tom Dean