matlab与C++以.mat文件方式进行数据相互流动-白红宇

年前，放假回家之前，使用了C++与matlab之间的数据的互动的一个实验，感觉效果挺好。初步达到了目的，所以整理下来方便大家使用。减少大家编程学习的时间。

希望对你们有用。

                               
#include "mat.h"<br data-filtered="filtered"><br data-filtered="filtered">void example8()
{ 
　　 
const
char
**fnames;       
/* pointers to field names */
    
const
mwSize *dims;
    
mxArray    *tmp, *fout;
    
char
*pdata=NULL;
    
int
i_field, nfields;
    
mxClassID  *classIDflags;
    
mwIndex    j_struct;
    
mwSize     NumStructRecords;
    
mwSize     ndim;
    
    
MATFile *pMF;
    
mxArray *pRoad, *pOut;
    
int
status;
    
const
char
*file = 
"ContourRoadResults_AfterWidthEtcCorrect_4_ZY.mat"
;
    
    
printf
(
"Opening file %s...\n\n"
, file);
    
pMF = matOpen(file, 
"u"
);
    
pRoad=matGetVariable(pMF, 
"ContourRoadResults"
);
   
    
/* get input arguments */
    
nfields = mxGetNumberOfFields(pRoad);
    
NumStructRecords = mxGetNumberOfElements(pRoad);
    
/* allocate memory  for storing classIDflags */
    
classIDflags = (mxClassID*) mxCalloc(nfields, 
sizeof
(mxClassID));
    
    
/* check empty field, proper data type, and data type consistency;
     
* and get classID for each field. */
    
for
(i_field=0; i_field<nfields; i_field++)
    
{ 
        
for
(j_struct = 0; j_struct < NumStructRecords; j_struct++)
        
{ 
            
tmp = mxGetFieldByNumber(pRoad, j_struct, i_field);
            
if
(tmp == NULL)
            
{ 
                
printf
(
"%s%d\t%s%d\n"
, 
"FIELD: "
, i_field+1, 
"STRUCT INDEX :"
, j_struct+1);
                
//mexErrMsgIdAndTxt( "MATLAB:phonebook:fieldEmpty", "Above field is empty!");
            
}
            
if
(j_struct==0)
            
{ 
                
if
( (!mxIsChar(tmp) && !mxIsNumeric(tmp)) || mxIsSparse(tmp)) { 
                    
printf
(
"%s%d\t%s%d\n"
, 
"FIELD: "
, i_field+1, 
"STRUCT INDEX :"
, j_struct+1);
                   
// mexErrMsgIdAndTxt( "MATLAB:phonebook:invalidField",
                   
//         "Above field must have either string or numeric non-sparse data.");
                
}
                
classIDflags[i_field]=mxGetClassID(tmp);
            
}
            
else
            
{ 
                
if
(mxGetClassID(tmp) != classIDflags[i_field])
                
{ 
                    
printf
(
"%s%d\t%s%d\n"
, 
"FIELD: "
, i_field+1, 
"STRUCT INDEX :"
, j_struct+1);
                    
//mexErrMsgIdAndTxt( "MATLAB:phonebook:invalidFieldType",
                    
//        "Inconsistent data type in above field!");
                
} 
else
if
(!mxIsChar(tmp) &&
                        
((mxIsComplex(tmp) || mxGetNumberOfElements(tmp)!=1))){ 
                    
printf
(
"%s%d\t%s%d\n"
, 
"FIELD: "
, i_field+1, 
"STRUCT INDEX :"
, j_struct+1);
                    
//mexErrMsgIdAndTxt( "MATLAB:phonebook:fieldNotRealScalar",
                    
//        "Numeric data in above field must be scalar and noncomplex!");
                
}
            
}
        
}
    
}
    
    
/* allocate memory  for storing pointers */
    
fnames = (
const
char
**)mxCalloc(nfields, 
sizeof
(*fnames));
    
/* get field name pointers */
    
for
(i_field=0; i_field< nfields; i_field++){ 
        
fnames[i_field] = (
char
*)mxGetFieldNameByNumber(pRoad,i_field);
    
}
    
/* create a 1x1 struct matrix for output  */
    
pOut = mxCreateStructMatrix(1,1,nfields, fnames);
    
mxFree((
void
*)fnames);
    
ndim = mxGetNumberOfDimensions(pRoad);
    
dims = mxGetDimensions(pRoad);
    
for
(i_field=0; i_field<nfields; i_field++) { 
        
/* create cell/numeric array */
        
if
(classIDflags[i_field] == mxCHAR_CLASS) { 
            
fout = mxCreateCellArray(ndim, dims);
        
}
else
{ 
            
fout = mxCreateNumericArray(ndim, dims, classIDflags[i_field], mxREAL);
            
pdata = (
char
*)mxGetData(fout);
        
}
        
/* copy data from input structure array */
        
for
(j_struct=0; j_struct<NumStructRecords; j_struct++) { 
            
tmp = mxGetFieldByNumber(pRoad,j_struct,i_field);
            
if
( mxIsChar(tmp)) { 
                
mxSetCell(fout, j_struct, mxDuplicateArray(tmp));
            
}
else
{ 
                
mwSize     sizebuf;
                
sizebuf = mxGetElementSize(tmp);
                
memcpy
(pdata, mxGetData(tmp), sizebuf);
                
pdata += sizebuf;
            
}
        
}
        
/* set each field in output structure */
        
mxSetFieldByNumber(pOut, 0, i_field, fout);
    
}
    
matPutVariable(pMF, 
"OutputResult_Convert"
,pOut);
    
mxFree(classIDflags);
    
if
(matClose(pMF) != 0) { 
        
printf
(
"Error closing file %s\n"
,file);
        
return
;
    
}
    
printf
(
"Done\n"
);
    
return
;
}
          
        

项目需要进行事先的C++ MEX混合编程的标准配置，再此不再赘述。要提醒的是，需要加入的头文件是#include "mat.h"。另外，具体的其他函数，请参照matlab的 MAT文件的读写的相关内容。

这个帮助对相关函数说明比较详细，参照相关的demo文件，你就能很快上手。

祝愿能解决你的问题！

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本文转自wenglabs博客园博客，原文链接：http://www.cnblogs.com/arxive/p/5223671.html

，如需转载请自行联系原作者