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Cpp to Mex conversion

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How can I do a cpp conversion to mex?

  1 Comment

James Tursa
James Tursa on 17 Jun 2019
Please post more details. Have you looked at the examples in the doc?

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Accepted Answer

James Tursa
James Tursa on 18 Jun 2019
Looks like you have a mismatch with variable types, probably an older piece of code that you are trying to compile on a newer MATLAB version. E.g., the code probably has this definition:
const int *DimsBness;
when it should be this:
const mwSize *DimsBness;
And you probably have something like this:
const int *dims;
or this
int dims[] = {2,3}; /* or whatever */
when it should be this:
const mwSize *dims;
or this
mwSize dims[] = {2,3}; /* or whatever */
Simply update the code with the required types to fix these errors.


Stelios Fanourakis
Stelios Fanourakis on 19 Jun 2019
Thanks James. I made it run and end up with a file having the extension of .mexmaci64 that I cannot do anything with it. I cannot open it, I cannot run it.
How do I convert the .mexmaci64 to just .m file
James Tursa
James Tursa on 19 Jun 2019
Please show the command you are using to compile the mex routine. And then show how you are trying to call the mex routine. Mex routines can be called just like any other regular function by using the function name and an argument list.
Stelios Fanourakis
Stelios Fanourakis on 20 Jun 2019
I used this command to create the .mexmaci64
mex -compatibleArrayDims BoneSegmentationDP.cpp
I tried to call it but I get the error of "Not correct or not enough input arguments".
I cannot open to edit this .mexmaci64. I cannot find any other function in the files to call it so to know how many inputs and what inputs it requires.
I also attach both cpp and .mexmaci64 so you tell me what am I doing wrong. Can you open .mexmaci64? Can you tell me its inputs?

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More Answers (1)

Suryaansh Mata
Suryaansh Mata on 18 Jun 2019
You can use the inbuilt MEX functionality to make use of the source code in C/C++ in MATLAB. Follow the step-by-step detailed instructions given at for the same.


Stelios Fanourakis
Stelios Fanourakis on 18 Jun 2019
I use the line
mex SegmentBone.cpp
This should do the compiling from cpp to Mex. However, I get the error
mex SegmentBoneDP.cpp
Building with 'Xcode Clang++'.
Error using mex
/Users/steliosphanourakes/Desktop/Matlab/DesMoines/karadokei -
Copy/FANOURAKIS_STELIOS12/20190516144930/SegmentBoneDP.cpp:17:17: error: assigning to 'const int *' from
incompatible type 'const mwSize *' (aka 'const unsigned long *')
DimsBness = mxGetDimensions(prhs[0]);
/Applications/ note: expanded from macro 'mxGetDimensions'
#define mxGetDimensions mxGetDimensions_730
/Users/steliosphanourakes/Desktop/Matlab/DesMoines/karadokei -
Copy/FANOURAKIS_STELIOS12/20190516144930/SegmentBoneDP.cpp:30:15: error: no matching function for call to
plhs[0] = mxCreateNumericArray(2,DimsBness,mxDOUBLE_CLASS,mxREAL);
/Applications/ note: expanded from macro 'mxCreateNumericArray'
#define mxCreateNumericArray mxCreateNumericArray_730
/Applications/ note: candidate function not viable: no known
conversion from 'const int *' to 'const mwSize *' (aka 'const unsigned long *') for 2nd argument
mxCreateNumericArray(mwSize ndim, const mwSize *dims, mxClassID classid, mxComplexity flag);
/Applications/ note: expanded from macro 'mxCreateNumericArray'
#define mxCreateNumericArray mxCreateNumericArray_730
2 errors generated.
Anyone who can responsibly help me?
Maria Cristina Bustos Rodriguez
I solved that mxCreateNumericArray_730 error by putting this warning:
"mex -DMX_COMPAT_32 yourcode.cpp "

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