Error when m-file calls cpp-file

2013 5 2
2 个回答
回答已采纳
3 次查看（30 天）

0 个投票

I have a folder that implements the Bayesian Color Constancy, and it contains .m files and .cpp files. When some .m file calls a .cpp file, MATLAB yields: ??? Undefined function or method ‹The functions' name› for input arguments of type ‹double›. although I have everything in path.
Do i need to install something special in order to make MATLAB recognize this file?

请先登录，再回答此问题。

 采纳的回答

José-Luis
José-Luis 2013-5-2

1 个投票

You cannot call directly cpp files from Matlab. You need to use mex to compile cpp file into a format that Matlab can understand.
doc mex
Once it is compiled you can call it directly from Matlab. As it stands, what the error message is telling you is that there is no function with that name that Matlab understand. The file might very well be there, but it is not possible to read it.

3 个评论
显示 1更早的评论 隐藏 1更早的评论

Elysi Cochin
Elysi Cochin 2013-5-2
编辑：Elysi Cochin 2013-5-2
sir how to use mex to compile cpp file.... please do reply sir.... i dont know how to convert into mex file.... please do reply sir.... it would great help for me sir.....
José-Luis
José-Luis 2013-5-2
Have you tried reading the documentation? Please type
doc mex
in the command line.
In a perfect world, if everything is already set up right:
mex your_file.cpp
should suffice, and produce a function your_file() that you can then call from Matlab.
Please accept an answer if it helps you.
Elysi Cochin
Elysi Cochin 2013-5-2
sir i didnt understand the document much...
the code i used is from the link http://people.kyb.tuebingen.mpg.de/pgehler/colour/index.html
and in that the bayesiancc contains the cpp files i'm working on...
in the a function logp = logp_X(X,logemp,lambda)
the mex file is called...
n_k = mex_histc(X,nBins);
just before this line i added...
mex mex_histc.cpp
n_k = mex_histc(X,nBins);
but this i got error as
Error mex_histc.cpp: 17 illegal statement termination
Error mex_histc.cpp: 17 skipping `unsigned' `int'
Error mex_histc.cpp: 17 undeclared identifier `nBins'
Error mex_histc.cpp: 18 illegal statement termination
Error mex_histc.cpp: 18 skipping `double'
Error mex_histc.cpp: 18 undeclared identifier `X'
Error mex_histc.cpp: 18 type error: pointer expected
Error mex_histc.cpp: 18 operands of = have illegal types `int' and `pointer to double'
Error mex_histc.cpp: 20 illegal statement termination
Error mex_histc.cpp: 20 skipping `unsigned' `int'
Error mex_histc.cpp: 20 undeclared identifier `npts'
Error mex_histc.cpp: 21 illegal statement termination
Error mex_histc.cpp: 21 skipping `unsigned' `int'
Error mex_histc.cpp: 21 undeclared identifier `ndims'
Error mex_histc.cpp: 43 illegal use of type name `mwSize'
Warning mex_histc.cpp: 43 Statement has no effect
Error mex_histc.cpp: 43 syntax error; found `dims' expecting `;'
Error mex_histc.cpp: 43 undeclared identifier `dims'
Error mex_histc.cpp: 43 type error: pointer expected
Warning mex_histc.cpp: 43 Statement has no effect
Error mex_histc.cpp: 44 type error: pointer expected
Error mex_histc.cpp: 45 type error: pointer expected
Error mex_histc.cpp: 47 too many errors
C:\PROGRA~1\MATLAB\R2009B\BIN\MEX.PL: Error: Compile of 'mex_histc.cpp' failed.
??? Error using ==> mex at 221
Unable to complete successfully.
Error in ==> logp_X at 11
mex mex_histc.cpp
Error in ==> rosenberg at 158
logp = logp_X(X,logemp,lambda);
Error in ==> sample_run at 15
Lrb = rosenberg(I,mask,logemp);
please can you tell me what i should do?? please do reply sir....

请先登录，再进行评论。

更多回答（1 个）

José-Luis
José-Luis 2013-5-2

1 个投票

Are you using linux?

2 个评论
显示 无 隐藏 无

Elysi Cochin
Elysi Cochin 2013-5-2
no sir i'm using windows 7
José-Luis
José-Luis 2013-5-2
Then you need to compile it. I looked at the download and a compiled linux version is provided. There is a Makefile provided to help with the dependencies or whatnot. You should probably contact the author for help if you want to do in Windows.

请先登录，再进行评论。

类别

在 帮助中心 和 File Exchange 中查找有关 Write C Functions Callable from MATLAB (MEX Files) 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by