Why do I get a, Invalid MEX-file error .

I'm trying to run a mex file compiled in VS2010, but when I call it from Matlab the prompt return the next error message.

Invalid MEX-file 'C:..\MyFunction.mexw32': The specified procedure could not be found.

Why?

[stefano davoli]

Same problem. Any sol found?

[James Tursa]

@Stefano: What are your specific circumstances? (Compiler, MATLAB versions, how did you do the compile, etc.)

[Image Analyst]

I don't believe the new 64 bit MATLAB versions can run 32 bit DLLs. At least I couldn't call one of mine when I tried. How many bits is your OS and MATLAB?

[Walter Roberson]

In MS Windows (and OS-X, and Linux) 64 bit executables cannot call 32 bit libraries. This is a limitation of the operating system architecture.

(I have never encountered an operating system that allowed this, but I could not say for sure that no operating system allows it.)

Answer 1

[Image Analyst]

How are you trying to run the mex file? As I understand it you don't run these, you call them from an m-file since they are basically DLLs. What happens if you say

>> which -all MyFunction

on the command line? Are you sure it's on your search path? If you say "path" does the folder where the mex file lives appear on the path?

[Walter Roberson]

Also, are you trying to run it from a 32 bit MATLAB or a 64 bit MATLAB ? .mexw32 is only for 32 bit MATLAB.

Answer 2

[Ken Atwell]

Could your MEX-File require another .DLL, and it is that DLL that cannot be found? Use a tool like Dependency Walker to display the functions available inside the MEX-File ("mexFunction" at a minimum should be there), and anything it may depend on. Anything in red may not be visible to MATLAB.