How do I run codes in environments other than MATLAB default folder?

I met the problem when I tried to run the following code written in a script file on my desktop,

[xasterisk,value]=fminsearch(@(x)100*(x(2)-x(1)^2)^2+(1-x(1))^2,[0,0])

then, I get the error "Attempt to execute SCRIPT fminsearch as a function:" then, I copied the code to the command window, and I got the same error. Finally, I decided to change the current folder to MATLAB folder, and the error disappears. So I guess the problem is because some environment setting issues, i.e. I can't visit fminsearch on desktop (Am I right?). So my question is how can I run codes on other folders that I assign (in my case, I usually save files, both scripts and function files on desktop)?

Answer 1

[Walter Roberson]

Go back to the other location and ask for the output of

which -all fminsearch

and tell us what the result is.

The expected output would be in somewhere under your MATLAB installation directory in toolbox/matlab/optimfun/fminsearch.m