Problem converting std::vector type to mwArray

Hello,

I am newbie usign Matlab C++ libraries.I am trying to convert a vector, for example Powervector, to the mwArray type so that by matlab function can use it. The Powervector has the following format in C++, std::vector<double> Powervector . Code that I use:

mwArray Tmsa(1, TotalPower.size(), mxDOUBLE_CLASS);
Tmsa.SetData(&TotalPower[0], TotalPower.size());

I have a problem when I debbug it. Debbuger show this message:

 _"An unhandled exception of type 'System.AccessViolationException' occurred in DevicePrognosis.exe
Additional information: Attempted to read or write protected memory. This is often an indication that other memory is corrupt."_

Any idea how can I fix it?

Thank you.

Answer 1

[Kaustubha Govind]

Strange, seems like that should work. How about if you try the documentation example:

double rdata[4] = {1.0, 2.0, 3.0, 4.0};
mwArray a(2, 2, mxDOUBLE_CLASS);
a.SetData(rdata, 4);

Just want to see if the issue has something to do with STL containers or heap-allocated data.

[enrique nares]

Hello Kaustubha!

I tried with the documentation answer too. It doesn't works and the same problem occurs. Any Idea?

Thanks in advance.

[Kaustubha Govind]

Then it looks like there is some other issue with your application. Have you initialized the MCR by calling mclInitializeApplication? There is an example in the documentation that does a similar set of commands as I suggested in my initial answer. Type "edit([matlabroot '/extern/examples/compiler/matrixdriver.cpp'])" at the MATLAB prompt to see it.

Answer 2

[enrique nares]

Hello,

I used the documentation example and I found the answer. I forgot mclInitializeApplication() function. Now it works but I have another problem. I have a std::vector<string> str and I want to pass it into mwArray. Any Idea how can I do that?

Thanks in advance.

[Kaustubha Govind]

If you need to create a char matrix, you might be able to use this constructor: http://www.mathworks.com/help/releases/R2011b/toolbox/compiler/mwarraymwsizenum_stringsconstcharstr.html

If you need a cell-array of strings, you probably need to loop over each element and use the Get and Set methods as in the example here: http://www.mathworks.com/help/releases/R2011b/toolbox/compiler/voidsetconstmwarrayarr.html