Learning how to use C++ with Matlab files

Question

Hi guys!
I'm Ph.D  student who needs to run thousands of mathematical simulations. Actually I'm working in MatLab, but due the massive quantity of simulations, I decided to make some tests in C++ in order to improve the time of the computations.
Well the thing is that all my data it's in mat files (Matlab filetype) and i tried three things for access them:
Use the library <fstream> but i found extremely complicated, specially with double numbers. (In fact i have to convert all my data to a text raw file)
Use the native API of C++ from Matlab, but i get the error
Warning: You are using gcc version "4.5.2". The version
currently supported with MEX is "4.3.4".
For a list of currently supported compilers see:
http://www.mathworks.com/support/compilers/current_release/
and until now i don't know how to resolve it.
Finally i found one library  http://sourceforge.net/projects/matio/  which in theory can handle mat files in C++ but I haven't could make it work in this test example http://na-wiki.csc.kth.se/mediawiki/index.php/MatIO:
#include <matio.h>
int main(void)
const double a[5] = {43.5, 5432.434, 3.32, 0.0001, 88834.0};
mat_t *mat;
matvar_t *matvar;
int dims[2] = {1,5};
mat = Mat_Open("simple.mat",MAT_ACC_RDWR);
if(mat)
matvar = Mat_VarCreate("vec1",MAT_C_DOUBLE,MAT_T_DOUBLE,2,dims,a,0);
Mat_VarWrite( mat, matvar, 0);
Mat_VarFree(matvar);
Mat_Close(mat);
else
return 1;
return 0;
because i get this:
/home/mikesol/projects/test/build> make
Scanning dependencies of target test
[100%] Building CXX object CMakeFiles/test.dir/main.cpp.o
/home/mikesol/projects/test/main.cpp: In function ‘int main()’:
/home/mikesol/projects/test/main.cpp:16:73: error: invalid conversion from ‘const void*’ to ‘void*’
/home/mikesol/projects/test/main.cpp:16:73: error: initializing argument 6 of ‘matvar_t* Mat_VarCreate(const char*, int, int, int, int*, void*, int)’
make[2]: *** [CMakeFiles/test.dir/main.cpp.o] Error 1
make[1]: *** [CMakeFiles/test.dir/all] Error 2
make: *** [all] Error 2
*** Failed ***
i'm not so good in C++ to improve the code or know what is wrong.  I'm sorry for that.
Summarizing: I'm stuck, so any help will be welcome.
Thanks in advance.

Answer 1

thanks to all,
@ngoonee: I'm going to try the solution described in your post https://bbs.archlinux.org/viewtopic.php?id=86809.
@tavianator: Thanks for the solution, but now there are some "undefined reference" in the compilation
/home/mikesol/projects/test/build> make
[100%] Building CXX object CMakeFiles/test.dir/main.cpp.o
Linking CXX executable test
CMakeFiles/test.dir/main.cpp.o: In function `main':
/home/mikesol/projects/test/main.cpp:14: undefined reference to `Mat_Open'
/home/mikesol/projects/test/main.cpp:18: undefined reference to `Mat_VarCreate'
/home/mikesol/projects/test/main.cpp:19: undefined reference to `Mat_VarWrite'
/home/mikesol/projects/test/main.cpp:21: undefined reference to `Mat_VarFree'
/home/mikesol/projects/test/main.cpp:22: undefined reference to `Mat_Close'
collect2: ld returned 1 exit status
make[2]: *** [test] Error 1
make[1]: *** [CMakeFiles/test.dir/all] Error 2
make: *** [all] Error 2
*** Failed ***
I will return later to work in that. Thanks to all.