Thread Subject: Error from using dgecon of LAPACK and BLAS in R2009a

I try to write down a mex file using and , in Matlab R2009a.
But get error LNK2019.
I have tried such codes in R2008b, there no such errors.
I am looking forward your help.

-----------------------My code---------------------------
#include "mex.h"
#include "matrix.h"
#include <stdlib.h>
#include "blas.h"
#include <math.h>
#include <string.h>

void dgetrf(const int *M, const int *N, double A[], const int *LDA,
int IPIV[], int *INFO);
void dgecon(const char *NORM, const int *N, const double A[],
const int *LDA, const double *ANORM, double *RCOND, double WORK[],
int IWORK[], int *INFO);
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{
   .. code that call dgetrf and dgecon
}

-----------------------My command in Matlab -----------------
mex ndbackslash.cpp "D:\Program Files\MATLAB\R2009a\extern\lib\win64\microsoft\libmwlapack.lib" "D:\Program Files\MATLAB\R2009a\extern\lib\win64\microsoft\libmwblas.lib"

-----------------------Debug errors -----------------
C:\USERS\ALIN\APPDATA\LOCAL\TEMP\MEX_O9~1\ndbackslash.obj D:\PROGRA~2\MATLAB\R2009A\EXTERN\LIB\WIN64\MICROS~1\libmwlapack.lib D:\PROGRA~2\MATLAB\R2009A\EXTERN\LIB\WIN64\MICROS~1\libmwblas.lib
   Creating library C:\USERS\ALIN\APPDATA\LOCAL\TEMP\MEX_O9~1\templib.x and object C:\USERS\ALIN\APPDATA\LOCAL\TEMP\MEX_O9~1\templib.exp
ndbackslash.obj : error LNK2019: unresolved external symbol "void __cdecl dgecon(char const *,int const *,double const * const,int const *,double const *,double *,double * const,int * const,int *)" (?dgecon@@YAXPEBDPEBHQEBN1PEBNPEANQEANQEAHPEAH@Z) referenced in function "void __cdecl compute_lu(double *,int,int *,double *,int *,int)" (?compute_lu@@YAXPEANHPEAH01H@Z)
ndbackslash.obj : error LNK2019: unresolved external symbol "void __cdecl dgetrf(int const *,int const *,double * const,int const *,int * const,int *)" (?dgetrf@@YAXPEBH0QEAN0QEAHPEAH@Z) referenced in function "void __cdecl compute_lu(double *,int,int *,double *,int *,int)" (?compute_lu@@YAXPEANHPEAH01H@Z)
ndbackslash.mexw64 : fatal error LNK1120: 2 unresolved externals

NB: error LNK2019: unresolved external symbol "void __cdecl dgecon

"Renwen Lin" <linrenwen@gmail.com> wrote in message <h5bb4h$ee8$1@fred.mathworks.com>...
> I try to write down a mex file using and , in Matlab R2009a.
> But get error LNK2019.
> I have tried such codes in R2008b, there no such errors.
> I am looking forward your help.
>
> -----------------------My code---------------------------
> #include "mex.h"
> #include "matrix.h"
> #include <stdlib.h>
> #include "blas.h"
> #include <math.h>
> #include <string.h>
>
> void dgetrf(const int *M, const int *N, double A[], const int *LDA,
> int IPIV[], int *INFO);
> void dgecon(const char *NORM, const int *N, const double A[],
> const int *LDA, const double *ANORM, double *RCOND, double WORK[],
> int IWORK[], int *INFO);
> void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
> {
> .. code that call dgetrf and dgecon
> }
>
> -----------------------My command in Matlab -----------------
> mex ndbackslash.cpp "D:\Program Files\MATLAB\R2009a\extern\lib\win64\microsoft\libmwlapack.lib" "D:\Program Files\MATLAB\R2009a\extern\lib\win64\microsoft\libmwblas.lib"
>
> -----------------------Debug errors -----------------
> C:\USERS\ALIN\APPDATA\LOCAL\TEMP\MEX_O9~1\ndbackslash.obj D:\PROGRA~2\MATLAB\R2009A\EXTERN\LIB\WIN64\MICROS~1\libmwlapack.lib D:\PROGRA~2\MATLAB\R2009A\EXTERN\LIB\WIN64\MICROS~1\libmwblas.lib
> Creating library C:\USERS\ALIN\APPDATA\LOCAL\TEMP\MEX_O9~1\templib.x and object C:\USERS\ALIN\APPDATA\LOCAL\TEMP\MEX_O9~1\templib.exp
> ndbackslash.obj : error LNK2019: unresolved external symbol "void __cdecl dgecon(char const *,int const *,double const * const,int const *,double const *,double *,double * const,int * const,int *)" (?dgecon@@YAXPEBDPEBHQEBN1PEBNPEANQEANQEAHPEAH@Z) referenced in function "void __cdecl compute_lu(double *,int,int *,double *,int *,int)" (?compute_lu@@YAXPEANHPEAH01H@Z)
> ndbackslash.obj : error LNK2019: unresolved external symbol "void __cdecl dgetrf(int const *,int const *,double * const,int const *,int * const,int *)" (?dgetrf@@YAXPEBH0QEAN0QEAHPEAH@Z) referenced in function "void __cdecl compute_lu(double *,int,int *,double *,int *,int)" (?compute_lu@@YAXPEANHPEAH01H@Z)
> ndbackslash.mexw64 : fatal error LNK1120: 2 unresolved externals
>
> NB: error LNK2019: unresolved external symbol "void __cdecl dgecon

You probably have to use stdcall convention.

Bruno

Bruno, Thanks so much,

After read few introductions of _stdcall. I think A __stdcall is supposed to deal with function's arguments, and I can not understood why it is needed here. It seems my problem is mex compile can not identify the function rather than its arguments.

Hope you can explain it a little more for me.


Lin Renwen

"Renwen Lin" <linrenwen@gmail.com> wrote in message <h5bs8j$6pd$1@fred.mathworks.com>...
> Bruno, Thanks so much,
>
> After read few introductions of _stdcall. I think A __stdcall is supposed to deal with function's arguments, and I can not understood why it is needed here. It seems my problem is mex compile can not identify the function rather than its arguments.
>
> Hope you can explain it a little more for me.

The calling convention affects how arguments are put on the stack, but also have the function name are decorated and exported.

There is a tool to inspect what are the function names in a library. I can't recall it right now.

Bruno

"Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <h5btue$rea$1@fred.mathworks.com>...
> "Renwen Lin" <linrenwen@gmail.com> wrote in message <h5bs8j$6pd$1@fred.mathworks.com>...
> > Bruno, Thanks so much,
> >
> > After read few introductions of _stdcall. I think A __stdcall is supposed to deal with function's arguments, and I can not understood why it is needed here. It seems my problem is mex compile can not identify the function rather than its arguments.
> >
> > Hope you can explain it a little more for me.
>
> The calling convention affects how arguments are put on the stack, but also have the function name are decorated and exported.
>
> There is a tool to inspect what are the function names in a library. I can't recall it right now.
>
> Bruno

Depends on the platform. For Windows it's "depends" for UNIX, "nm". Also bear in mind that the naming convention may dgecon_ a common way to mix C with FORTRAN.

I have identify the problem.
My purpose is to solve X from A*X =B;

The first thing I need is LU decomposition of A.

Matlab use DGETRF caling DGECON for LU-decomposition in early version. But Use DGETRF calling DLACN2 in R2009a.

Thanks!

Lin Renwen

Hi Bruno,

Thanks a lot :)

I think I understood some about your words.

and I find the functions in lib by checking <blas.h> in '\extern\include\' fileflip.

Lin Renwen