MATLAB: Using matlabfunction to declare variables

matlabfunctionSymbolic Math Toolboxvars

I have three equations with names 'equn1, equn2, equn3'. Variables in those equations are declared as :
lam = sym('lam', [1 3] ).
To solve those equations, i am writing the code like this :
solu_fsolve = []; value = [];  lam(1)  = 0; lam(2) = 0; lam(3) = 0;
fh = matlabFunction([equn1;equn2;equn3],'vars',{[ lam(1), lam(2), lam(3)]});
options = optimset('Display','off','TolFun',eps);
[solu_fsolve,value] = fsolve(fh, [ 1,1,1] ,options ) ;
But, when i execute this code , i am getting an error like :
??? Error using ==> sym.matlabFunction>checkVars at 155
Variable names must be valid MATLAB variable names.  
Error in ==> sym.matlabFunction at 104
vars = checkVars(funvars,opts);
Can anyone please tell me how to declare the array as variables in matlabfunction?
Please help.
–kalpana

Best Answer

When you execute the first line of code you make lam a symbolic vector:
lam = sym('lam', [1 3] )
lam =
[ lam1, lam2, lam3]
However, you later change those variables to symbolic zeros instead of leaving them as variables.
lam(1)  = 0; lam(2) = 0; lam(3) = 0;
Remove that line of code and I expect that matlabFunction will work just fine.
Alan Weiss
MATLAB mathematical toolbox documentation
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