How to find Matlab version to be used in the mex file header

I create a mex file that compiles and works properly in R2010b and up, versions I have at my work. But I need the same file be used in R2010a, since that's the version I have in my laptop. If I used in R2010 I have an error. I found the code need it to make it work. But every time I switch I have to comment and uncomment. Is there any way to find Matlab's version in the header? Let me give some code:

        #include <stdlib.h>
        #include <vector>
        #include <queue>
        #include <limits>
        #include <utility>
        #include <map>
        #include <assert.h>
        #include <stdio.h>
      /* #ifdef _CHAR16T //for matlab 2010a
      #define CHAR16_T
      #endif */
      #include "mex.h"
      #include "matrix.h"
      using namespace std;
........code ............

The commented section is my fix. I want to find Matlab's version and put an if statement so it automatically applies my fix. I try this:

      int i;
      int j;
      sscanf(version,'%d.%d %*s',&i, &j)
      #if i<=7 && j<11
      #ifdef _CHAR16T //for matlab 2010a
      #define CHAR16_T
      #endif
      #endif

but it did not work since c++ did not find the "version" variable defined in matlab. Does somebody know how to do that? I really appreciate any help!

Answer 1

[Jan]

Does the problem concern the Matlab version, or is it caused by different compilers?

Would it work to check if CHAR16_T is defined already?

#ifndef CHAR16_T

Butr if the problem really concerns the Matlab version, I suggest to append a flag to the MEX call:

function myMex(varargin)
V = [100, 1] * sscanf(version, '%d', 2);  % Consider 7.10!
if V < 711  
  Flag = {'-DNEED_CHAR_16_T'};
else
  Flag = {};
end

mex(varargin{:}, Flag{:});

I started with some equivalen flags to distinguish Matlab 5.3 and 6.5. Meanwhile my enhanced MEX function has 500 lines, considers different mexopt.bat files, e.g. enable SSE2 commands under 32-bit Matlab, but avoid this under 64 bit, if MSVC2010 ist used, etc.

[Steven Lord]

V = [100, 1] * sscanf(version, '%d', 2);  % Consider 7.10!

The verLessThan function was introduced in release R2007a. You can wrap it in a try / catch statement if you need to run the code in release R2006b or earlier, and use this technique in the catch block to distinguish release R2006b and earlier releases.

Answer 2

[James Tursa]

Version info for mex routines can be found in this FEX submission:

https://www.mathworks.com/matlabcentral/fileexchange/67016-c-mex-matlab-version

Answer 3

[Kaustubha Govind]

You can use the ver command to obtain version information in MATLAB:

>> v=ver('MATLAB')

v = 

         Name: 'MATLAB'
      Version: '7.13'
      Release: '(R2011b)'
         Date: '08-Jul-2011'

However, it's not clear to me how you plan to use this information in your MEX-file. Since #defines are used by the pre-processor, what you're doing won't work at run-time. Do you plan to re-compile the C code every time before it is executed?