Unable to run a simple 'fsolve' example.

Hi,

While running the root2d example file provided with the 'fsolve' document, MATLAB is throwing the following error:

Unrecognized function or variable 'eml_allow_mx_inputs'.

Error in fsolve

The code for root2d file is below and the m-file is placed in the MATLAB directory:

function F = root2d(x)

F(1) = exp(-exp(-(x(1)+x(2)))) - x(2)*(1+x(1)^2);

F(2) = x(1)*cos(x(2)) + x(2)*sin(x(1)) - 0.5;

end

I am running the following syntax to solve 'root2d':

fun = @root2d;

x0 = [0,0];

x = fsolve(fun,x0)

[Walter Roberson]

Experiment with

restoredefaultpath; rehash toolboxcache

If that solves the problem then

savepath

[Shiv Tewari]

Thanks Walter. This syntax would come-in handy to fix any future path-related issues.

Answer 1

[Steven Lord]

My guess is that you accidentally added the toolbox/optim/eml directory under matlabroot to the MATLAB search path. If it is on the path, remove it from the path.

contains(path, "toolbox/optim/eml")

ans = logical
   0

When you run the following command it should not list the fsolve.m file in toolbox/optim/eml. It should list the one in toolbox/optim/optim.

which -all fsolve

/MATLAB/toolbox/optim/optim/fsolve.m

The version of the file in toolbox/optim/eml is only used by MATLAB Coder when you generate C or C++ code from a function that calls fsolve.

[Shiv Tewari]

Thanks Steven.

I saw that MATLAB was using the p-file for solving 'root2d,' I didn't know that MATLAB uses the m-file for solving the non-linear equation. As you suggested, I removed the path to the p-file and that did the trick.

I wonder how the path to the p-file got added to my MATLAB, because I didn't have this issue while using 'fsolve' ealier.