一、代码matrixMultiply.c 从自带例子中拷贝过来：

>> copyfile(fullfile(matlabroot,'extern','examples','refbook','matrixMultiply.c'),'.')>> ls mat*

>> ls mat*

matlab.mat  matrixMultiply.c  mattest.mat

>> fileattrib('matrixMultiply.c','+w')

cat matrixMultiply.c

/*=========================================================

* matrixMultiply.c - Example for illustrating how to use

* BLAS within a C MEX-file. matrixMultiply calls the

* BLAS function dgemm.

*

* C = matrixMultiply(A,B) computes the product of A*B,

* where A, B, and C are matrices.

*

* This is a MEX-file for MATLAB.

* Copyright 2009-2010 The MathWorks, Inc.

*=======================================================*/

#if !defined(_WIN32)

#define dgemm dgemm_

#endif

#include "mex.h"

#include "blas.h"

void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])

{

double *A, *B, *C; /* pointers to input & output matrices*/

size_t m,n,p; /* matrix dimensions */

/* form of op(A) & op(B) to use in matrix multiplication */

char *chn = "N";

/* scalar values to use in dgemm */

double one = 1.0, zero = 0.0;

A = mxGetPr(prhs[0]); /* first input matrix */

B = mxGetPr(prhs[1]); /* second input matrix */

/* dimensions of input matrices */

m = mxGetM(prhs[0]);

p = mxGetN(prhs[0]);

n = mxGetN(prhs[1]);

if (p != mxGetM(prhs[1])) {

mexErrMsgIdAndTxt("MATLAB:matrixMultiply:matchdims",

"Inner dimensions of matrix multiply do not match.");

}

/* create output matrix C */

plhs[0] = mxCreateDoubleMatrix(m, n, mxREAL);

C = mxGetPr(plhs[0]);

/* Pass arguments to Fortran by reference */

dgemm(chn, chn, &m, &n, &p, &one, A, &m, B, &p, &zero, C, &m);

}

二、编译：

>> mex -v matrixMultiply.c -lmwblas

详细模式已开。

... 正在查找编译器 'gcc-4.9'...

... 正在执行命令 'which gcc-4.9'...是('/usr/bin/gcc-4.9')。

... 正在执行命令 'gcc-4.9 -print-file-name=libstdc++.so'...是('/usr/lib/gcc/x86_64-linux-gnu/4.9/libstdc++.so')。

找到已安装的编译器 'gcc-4.9'。

Options file details

-------------------------------------------------------------------

Compiler location: /usr/bin/gcc-4.9

Options file: /home/mymotif/.matlab/R2017a/mex_C_glnxa64.xml

CMDLINE2 : /usr/bin/gcc-4.9 -pthread -Wl,--no-undefined -Wl,-rpath-link,/opt/local/MATLAB/R2017a/bin/glnxa64 -shared -O -Wl,--version-script,"/opt/local/MATLAB/R2017a/extern/lib/glnxa64/c_exportsmexfileversion.map" /tmp/mex_7030238084799_6443/matrixMultiply.o /tmp/mex_7030238084799_6443/c_mexapi_version.o -lmwblas -L"/opt/local/MATLAB/R2017a/bin/glnxa64" -lmx -lmex -lmat -lm -lstdc++ -o matrixMultiply.mexa64

CC : /usr/bin/gcc-4.9

DEFINES : -DTARGET_API_VERSION=700 -DUSE_MEX_CMD -D_GNU_SOURCE -DMATLAB_MEX_FILE

MATLABMEX : -DMATLAB_MEX_FILE

CFLAGS : -fexceptions -fPIC -fno-omit-frame-pointer -pthread

INCLUDE : -I"/opt/local/MATLAB/R2017a/extern/include" -I"/opt/local/MATLAB/R2017a/simulink/include"

COPTIMFLAGS : -O -DNDEBUG

CDEBUGFLAGS : -g

LD : /usr/bin/gcc-4.9

LDFLAGS : -pthread -Wl,--no-undefined -Wl,-rpath-link,/opt/local/MATLAB/R2017a/bin/glnxa64

LDTYPE : -shared

FUNCTIONMAP : "/opt/local/MATLAB/R2017a/extern/lib/glnxa64/mexFunction.map"

VERSIONMAP : "/opt/local/MATLAB/R2017a/extern/lib/glnxa64/c_exportsmexfileversion.map"

LINKEXPORT : -Wl,--version-script,"/opt/local/MATLAB/R2017a/extern/lib/glnxa64/mexFunction.map"

LINKEXPORTVER : -Wl,--version-script,"/opt/local/MATLAB/R2017a/extern/lib/glnxa64/c_exportsmexfileversion.map"

LINKLIBS : -lmwblas -L"/opt/local/MATLAB/R2017a/bin/glnxa64" -lmx -lmex -lmat -lm -lstdc++

LDOPTIMFLAGS : -O

LDDEBUGFLAGS : -g

MWCPPLIB : "/opt/local/MATLAB/R2017a/sys/os/glnxa64/libstdc++.so.6"

OBJEXT : .o

LDEXT : .mexa64

SETENV : CC="/usr/bin/gcc-4.9"

CXX="g++"

CFLAGS="-fexceptions -fPIC -fno-omit-frame-pointer -pthread -DTARGET_API_VERSION=700 -DUSE_MEX_CMD -D_GNU_SOURCE -DMATLAB_MEX_FILE "

CXXFLAGS="-fexceptions -fPIC -fno-omit-frame-pointer -pthread -std=c++11 -DTARGET_API_VERSION=700 -DUSE_MEX_CMD -D_GNU_SOURCE -DMATLAB_MEX_FILE "

COPTIMFLAGS="-O -DNDEBUG"

CXXOPTIMFLAGS="-O -DNDEBUG"

CDEBUGFLAGS="-g"

CXXDEBUGFLAGS="-g"

LD="/usr/bin/gcc-4.9"

LDXX="g++"

LDFLAGS="-pthread -Wl,--no-undefined -Wl,-rpath-link,/opt/local/MATLAB/R2017a/bin/glnxa64 -shared -lmwblas -L"/opt/local/MATLAB/R2017a/bin/glnxa64" -lmx -lmex -lmat -lm -lstdc++ -Wl,--version-script,"/opt/local/MATLAB/R2017a/extern/lib/glnxa64/mexFunction.map""

LDDEBUGFLAGS="-g"

GCC : /usr/bin/gcc-4.9

CPPLIBS : /usr/lib/gcc/x86_64-linux-gnu/4.9/libstdc++.so

MATLABROOT : /opt/local/MATLAB/R2017a

ARCH : glnxa64

SRC : /home/mymotif/matlab_workplace/matrixMultiply.c;/opt/local/MATLAB/R2017a/extern/version/c_mexapi_version.c

OBJ : /tmp/mex_7030238084799_6443/matrixMultiply.o;/tmp/mex_7030238084799_6443/c_mexapi_version.o

OBJS : /tmp/mex_7030238084799_6443/matrixMultiply.o /tmp/mex_7030238084799_6443/c_mexapi_version.o

SRCROOT : /home/mymotif/matlab_workplace/matrixMultiply

DEF : /tmp/mex_7030238084799_6443/matrixMultiply.def

EXP : matrixMultiply.exp

LIB : matrixMultiply.lib

EXE : matrixMultiply.mexa64

ILK : matrixMultiply.ilk

MANIFEST : matrixMultiply.mexa64.manifest

TEMPNAME : matrixMultiply

EXEDIR :

EXENAME : matrixMultiply

OPTIM : -O -DNDEBUG

LINKOPTIM : -O

CMDLINE1_0 : /usr/bin/gcc-4.9 -c -DTARGET_API_VERSION=700 -DUSE_MEX_CMD -D_GNU_SOURCE -DMATLAB_MEX_FILE -I"/opt/local/MATLAB/R2017a/extern/include" -I"/opt/local/MATLAB/R2017a/simulink/include" -fexceptions -fPIC -fno-omit-frame-pointer -pthread -O -DNDEBUG /home/mymotif/matlab_workplace/matrixMultiply.c -o /tmp/mex_7030238084799_6443/matrixMultiply.o

CMDLINE1_1 : /usr/bin/gcc-4.9 -c -DTARGET_API_VERSION=700 -DUSE_MEX_CMD -D_GNU_SOURCE -DMATLAB_MEX_FILE -I"/opt/local/MATLAB/R2017a/extern/include" -I"/opt/local/MATLAB/R2017a/simulink/include" -fexceptions -fPIC -fno-omit-frame-pointer -pthread -O -DNDEBUG /opt/local/MATLAB/R2017a/extern/version/c_mexapi_version.c -o /tmp/mex_7030238084799_6443/c_mexapi_version.o

-------------------------------------------------------------------

使用 'gcc-4.9' 编译。

/usr/bin/gcc-4.9 -c -DTARGET_API_VERSION=700 -DUSE_MEX_CMD -D_GNU_SOURCE -DMATLAB_MEX_FILE -I"/opt/local/MATLAB/R2017a/extern/include" -I"/opt/local/MATLAB/R2017a/simulink/include" -fexceptions -fPIC -fno-omit-frame-pointer -pthread -O -DNDEBUG /home/mymotif/matlab_workplace/matrixMultiply.c -o /tmp/mex_7030238084799_6443/matrixMultiply.o

In file included from /home/mymotif/matlab_workplace/matrixMultiply.c:18:0:

/opt/local/MATLAB/R2017a/extern/include/blas.h:585:0: warning: "dgemm" redefined

#define dgemm FORTRAN_WRAPPER(dgemm)

^

/home/mymotif/matlab_workplace/matrixMultiply.c:14:0: note: this is the location of the previous definition

#define dgemm dgemm_

^

/usr/bin/gcc-4.9 -c -DTARGET_API_VERSION=700 -DUSE_MEX_CMD -D_GNU_SOURCE -DMATLAB_MEX_FILE -I"/opt/local/MATLAB/R2017a/extern/include" -I"/opt/local/MATLAB/R2017a/simulink/include" -fexceptions -fPIC -fno-omit-frame-pointer -pthread -O -DNDEBUG /opt/local/MATLAB/R2017a/extern/version/c_mexapi_version.c -o /tmp/mex_7030238084799_6443/c_mexapi_version.o

/usr/bin/gcc-4.9 -pthread -Wl,--no-undefined -Wl,-rpath-link,/opt/local/MATLAB/R2017a/bin/glnxa64 -shared -O -Wl,--version-script,"/opt/local/MATLAB/R2017a/extern/lib/glnxa64/c_exportsmexfileversion.map" /tmp/mex_7030238084799_6443/matrixMultiply.o /tmp/mex_7030238084799_6443/c_mexapi_version.o -lmwblas -L"/opt/local/MATLAB/R2017a/bin/glnxa64" -lmx -lmex -lmat -lm -lstdc++ -o matrixMultiply.mexa64

MEX 已成功完成。

三、运行：

>> A = [1 3 5; 2 4 7];

>> B = [-5 8 11; 3 9 21; 4 0 8];

>> X = matrixMultiply(A,B)

X =

24 35 114

30 52 162