Trying to open a .dll file in MATLAB but I'm unable to. The error shown is "undefined function 'simplelw' for input arguments of type 'double'."

Basically, I have this script and my line of code is:

output=simplelw(sizex,sizey,seedx,seedy,wghtCoA,wghtCoB,wghtCoC,wghtCoD,gradientx,gradienty,imageCannyEdge,imageLoG,magnitude);

The error is

Undefined function 'simplelw' for input arguments of type 'double'.
Error in lwcontour (line 183)

output=simplelw(sizex,sizey,seedx,seedy,wghtCoA,wghtCoB,wghtCoC,wghtCoD,gradientx,gradienty,imageCannyEdge,imageLoG,magnitude);

Now, simplelw is a .dll file. This used to work in older versions of MATLAB, but not in 2012. Any ideas to what the problem is? I'm running a x64 version of MATLAB, could that be the problem?

I made sure that I'm in the correct directory (for example, when I try to open('simplelw.dll'), it opens, but I can't really see anything because it's a .dll.

Thanks!

[Walter Roberson]

Are you using 32 bit or 64 bit MATLAB? Is the dll 32 bit or 64 bit?

Answer 1

[Jan]

Is the DLLs a MEX function compiled for 32 bit? Then you cannot run it from a 64 bit Matlab version, because a MEXW64 file is required. There is no workaround to call a 32-bit DLL from a 64 bit Matlab version.

[Mahdi]

Thanks. That was the solution. Is there a way to still run it from 64 bit version though?

[Jan]

No. Either install a 32-bit Matlab on a 64-bit operating system, or invent a 64to32-bit-converter and get very rich.