How can I compile a MATLAB Engine application using Microsoft Visual Studio 9.0 or 10.0 ?

I would like to call MATLAB from my C/C++ application using the Engine interface. However, I would like to compile my project in the Microsoft Visual Studio 9.0 (2008) or Visual Studio 10.0 (2010) environment, instead of compiling it in the MATLAB environment.

Answer 1

[MathWorks Support Team]

To compile a MATLAB engine application in the Microsoft Visual Studio 9.0 (2008) or Microsoft Visual Studio 10.0 (2010) environments, perform the steps outlined below:

1. Open Microsoft Visual Studio and select

File->New->Project

and then select:

Visual C++ -> General -> Empty Project

Following this, enter the name of the project and its location in the indicated text areas and click OK.

2. Right-click on the SOURCE FILES folder in the SOLUTION EXPLORER and click Add -> "New Item...". Choose "C++ file (.cpp)", enter the name of the file as enginedemo.cpp. Click OK.

3. Copy the code from the source file: engwindemo.c, and paste it into this file enginedemo.cpp. The file engwindemo.c may be obtained from the following location:

 $MATLABROOT/extern/examples/eng_mat

where $MATLABROOT is the MATLAB root directory, and may be determined by entering the command:

matlabroot

at the MATLAB command prompt.

4. Right click on the project name and select PROPERTIES in the solution explorer to open the project properties. Once this window has opened, make the following changes:

a. Under C/C++ General, add the following directory to the field ADDITIONAL INCLUDE DIRECTORIES:

$MATLABROOT\extern\include

b. Under C/C++ Precompiled Headers, select "Not Using Precompiled Headers".

c. Under Linker General, add the directory to the field ADDITIONAL LIBRARY DIRECTORIES:

(For 32-bit Windows)

$MATLABROOT\extern\lib\win32\microsoft

(For 64-bit Windows)

$MATLABROOT\extern\lib\win64\microsoft

d. Under Configuration Properties ->Debugging

Add the following Target path in the Environment:

(for 32 bit MATLAB)

PATH=$matlabroot\bin\win32

(for 64-bit MATLAB)

PATH=$matlabroot\bin\win64 If you want to use an absolute path instead, use the following (with a semicolon at the end)

PATH=C:\Program Files\MATLAB\R2013a\bin\win32; (for 32 bit MATLAB)

PATH=C:\Program Files\MATLAB\R2013a\bin\win64; (for 64 bit MATLAB)

7. Under Linker Input, add the following names to the field marked ADDITIONAL DEPENDENCIES:

libmx.lib

libmat.lib

libeng.lib

8. If compiling on 64-bit Windows, change the target to x64 as mentioned on the following link:

https://www.microsoft.com/en-us/download/details.aspx?id=55984

You should now be able to build the executable.

9. Make sure that the following directory is in the PATH:

(For 32-bit Windows)

$MATLABROOT\bin\win32

(For 64-bit Windows)

$MATLABROOT\bin\win64

To do this, check the Windows system path by clicking on Start -> Right click on Computer -> Properties -> Advanced System Settings -> Environment variables -> System Variables -> Open "Path" for editing.

Note: If the machine has more than one MATLAB installed, the directory for the target platform must be ahead of any other MATLAB directory (for instance, when compiling a 64-bit application, the directory in the MATLAB 64-bit installation must be the first one on the PATH).

10. Build and execute the application.

[Dan]

I have followed all the steps. But still get error:

1>engdemo.obj : error LNK2019: unresolved external symbol _engClose referenced in function _main 1>engdemo.obj : error LNK2019: unresolved external symbol _mxGetClassName referenced in function _main 1>engdemo.obj : error LNK2019: unresolved external symbol _engGetVariable referenced in function _main 1>engdemo.obj : error LNK2019: unresolved external symbol _engOutputBuffer referenced in function _main

Any help? thanks!

[Jat]

I had the same issue when I skipped step 8, so I went back to fix that and it works fine now. Make sure you stick with either a 32-bit setting or a 64-bit setting. This also depends on your MATLAB version.

[Leon]

I used 64-bit MATLAB 2013a and 32-bit VS 2012, the answer is great. The only thing I want to add is in d. Under Configuration Properties ->Debugging

Add the following Target path in the Environment:

(for 32 bit MATLAB)

PATH=$matlabroot\bin\win32

(for 64-bit MATLAB)

PATH=$matlabroot\bin\win64

////////////////////////////////////////////

If we want to use a absolute path, we should type: for example,

PATH=D:\Program Files\MATLAB\R2013a\bin\win32; (for 32 bit MATLAB)

PATH=D:\Program Files\MATLAB\R2013a\bin\win64; (for 64 bit MATLAB)

Never forget the semicolon. It took me 3 hours to fix this problem.

[Ran Manor]

Your tip has probably saved me 3 hours. Thanks!

[Samuel Gray]

Oh, (at least with VS2015+) the IDE will use $(MATLABROOT) if MATLABROOT is defined in the environment variable tool (system pref over user). e.g. set MATLABROOT=c:\program files\etc check with the little gray boxes to the right of the line ("edit") and see what the compiler actually uses as the corresponding filespec for each element between semicolons.

Next, make sure that the target copy of Matlab is properly registered as a COM object:

https://www.mathworks.com/help/matlab/ref/regmatlabserver.html

I'm using a 2019a, 2020a & 2020b co-install and it works registered with the local account.

If you see a popup saying that it can't start blah@@blah in matlab version x when you have used version y in all the other strings above, this is why that is happening. It's pulling the COM target from the registry and that has to be fixed either by editing the registry or registering it through matlab.

I did name the cpp file the same as the project and I converted it into a plain text file (that will open and display properly in Notepad). This does not really matter, the project folder can be renamed and the project will still load properly as long as everything is referenced to the project folder (there is a VS environment macro for $(BuildDirectory)). This is a seperate issue that you might want to play around with after getting this to work at all because often it is good to work on copies of directories of working code, not try to do all mods to one folder full of code.

2. To create the project (and associated solution) in VS, start with project/solution/ add new project/ empty C++ project. Right-click on the SOURCE FILES folder in the SOLUTION EXPLORER and click Add -> "New Item...". Choose "C++ file (.cpp)", enter the name of the file (as enginedemo.cpp) as you wish. Click OK.

This can be changed after you get the project to build. You'll want to focus on changing the code, not renaming or removing objects in the solution, but sometimes that's necessary.

Make $(MATLABROOT)\bin\win64 the first matlab line in the path. (in the Windows environment).

Again make sure that you make configuration changes in the configuraiton that you want to use. The default is debug/x86. For 64-bit code you want to use debug/x64.

You won't need to restart or logout and back in to make changes effective but I did APPLY each change as I went along (the above could use a re-org) and clean & rebuild the project several times in the process of getting this to work. Don't forget to hit "apply" after setting each field. You can check the C++ & Linker "All Options" fields for the actual values used in the build.

Set the configuration for both debug and release by using "all configurations".

If you have any doubts about the paths, check the "edit" tab at the end of each line or use literally "PATH=C:\Program Files..." etc in the instructions above as indicated.

With semicolons at the end of all of the path-specifications so it looks like

c:\;c:\apps;$(AdditionalIncludes);

WRT the library files are indicated above, libmex.lib is probably what is meant instead of libmx.lib.

Be careful not to try to build win32 code (the default) when you want win64 code or vice-versa.

I suggest to start with something simple just call engOpen("") and get that to pop up the Matlab comand-window. Select the build config of interest (debug/x64) clean the project, build it, then run it in the debugger. Any missing pdb files should download off the Internet.

A very simple cpp file that will suffice to demonstrate the functionality is:

#include "stdafx.h"

#include "engine.h"

#include <iostream>

using namespace std;

int main()

{

Engine *eng;

eng=engOpen(""); // put a breakpoint here

(eng=showVisible(1); here if you want the normal Matlab GUI);

cout << "...now you see it...\n"

(eng=showVisible(0); hide the normal Matlab GUI but the engine window will still be visible);

engClose(eng); // put a breakpoint here

cout << "...now you don't!\n"

return 0;

}

And from there it's just a matter of what dll files your Matlab application requires beyond the standard 3. In a pinch, put them in the build folder with the .exe file.

See the other examples for some great tips on interacting with Matlab from C.

[Samuel Gray]

If using VS I'd at least look over these to see how the include directories can be set up in VS.

https://docs.microsoft.com/en-us/cpp/build/reference/vcpp-directories-property-page?view=msvc-160

https://docs.microsoft.com/en-us/cpp/build/create-reusable-property-configurations?view=msvc-160

https://social.msdn.microsoft.com/Forums/en-US/176c9a4b-9bcf-4c99-a721-9a6fe0d02239/what-is-the-difference-between-quotvc-directories-gt-include-directoriesquot-and?forum=vcprerelease

https://stackoverflow.com/questions/6883276/what-is-the-difference-between-include-directories-and-additional-include-dir

[Indhu Priyadharshini Govindasamy]

@Samuel Gray @Walter Roberson

Error :"C2371 'size_t': redefinition; different basic types"

I have followed the above steps and also changed the configuration settings to 64 bit in visual studio and matlab

and also i have added the matlab path in environment variable path but still i am getting this error.

Could anyone please help me to fix this?

Answer 2

[Kristen]

I have followed the setup and am able to build the program, however when I execute the program I get the following error and am unsure on how to fix it.

    'general.exe': Loaded 'C:\Users\Jakubk2\Documents\Visual Studio 2010\Projects\general\x64\Debug\general.exe', Symbols loaded.
    'general.exe': Loaded 'C:\Windows\System32\ntdll.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\kernel32.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\KernelBase.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\libmx.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\libmwresource_core.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Windows\System32\msvcp100.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\msvcr100.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\libmwi18n.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\boost_date_time-vc100-mt-1_49.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\boost_filesystem-vc100-mt-1_49.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\boost_system-vc100-mt-1_49.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Windows\System32\advapi32.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\msvcrt.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\sechost.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\rpcrt4.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\libexpat.dll', Binary was not built with debug information.
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\icuin49.dll', Binary was not built with debug information.
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\icuuc49.dll', Binary was not built with debug information.
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\icudt49.dll', Binary was not built with debug information.
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\icuio49.dll', Binary was not built with debug information.
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\libut.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\libmwfl.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Windows\System32\imagehlp.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\psapi.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\libmwMATLAB_res.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\boost_regex-vc100-mt-1_49.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Windows\System32\user32.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\gdi32.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\lpk.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\usp10.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\boost_serialization-vc100-mt-1_49.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\boost_signals-vc100-mt-1_49.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\boost_thread-vc100-mt-1_49.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\boost_log-vc100-mt-1_49.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Windows\System32\ws2_32.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\nsi.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\tbb.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Windows\System32\powrprof.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\setupapi.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\cfgmgr32.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\oleaut32.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\ole32.dll', Symbols loaded.
    'general.exe': Loaded 'C:\Windows\System32\devobj.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\tbbmalloc.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\zlib1.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Program Files\MATLAB\R2014a\bin\win64\libeng.dll', Cannot find or open the PDB file
    'general.exe': Loaded 'C:\Windows\System32\msvcr100d.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\imm32.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\msctf.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\cryptbase.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\uxtheme.dll', Symbols loaded (source information stripped).
    'general.exe': Loaded 'C:\Windows\System32\clbcatq.dll', Symbols loaded (source information stripped).
    The program '[5224] general.exe: Native' has exited with code 1 (0x1).

any advice on how to resolve this issue?

Thanks Kristen

[Kristen]

for some additional information i am running VS2010 and MATLAB 2014a

Answer 3

[Sergey Antonov]

A minute ago I have built my project successfully in Visual Studio 2010 (EXPRESS) x64 config. It was tricky a bit... It doesn't have x64 compiler by default. I had to install MS SDK 7.1. MS SDK 7.1 doesn't install when MSVS redistributables are already installed. Uninstalled them, reinstalled MS SDK... Then I tried to compile project. MSVS wrote error:

The "ConfigurationGeneral" rule is missing from the project.

After that I did some mad things for 2 hours. Finally, I found that it is a bug and all you need is just to install some KB: http://connect.microsoft.com/VisualStudio/feedback/details/519904. It is written, that premium and ultimate versions of MSVS don't have such problem.

Answer 4

[claudia mendez]

I have done it, and everything its fine, but what do I have to do if I want to change the function?

[Richa Gupta]

Contact MathWorks Technical Support.

[Vandana Ravichandran]

The function that is invoked in MATLAB (called using engEvalString) can be changed. If the function is found in the current folder inside MATLAB, that function is invoked. Otherwise, it looks for the function present on the MATLAB path. If you do not make any API changes (i.e. input/output arguments) to your MATLAB function, the C++ engine application does not need to be modified. Otherwise, it had to be modified appropriately.

[Samuel Gray]

...the string can be changed that is passed to engEvalString.

That string is equivalent to the string parsed by Matlab.

i.e. you want to run foo.m in Matlab by calling it from C, call engEvalString() with "foo" and the engine handle from your C code. If you want to get the function output back into C from Matlab, call the buffered i/o functions as shown in the other examples. They are pretty simple to understand and use at least for basic operations like text and binary i/o, but they're a good start to more complex i/o.