在Matlab中使用mex函数进行C/C++混合编程
wwwdownmacom 2014-11-08
最近写了个Matlab程序，好慢呐……所以开始学习Matlab与C/C++混合编程。下面写了个测试代码，显示一个Double类型矩阵中的元素。
源代码
#include "mex.h"
void displaySubscript( const mxArray *pArray, mwSize index );
// 入口函数
void mexFunction( int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[] ) {
// 源文件名后缀为.c时，所有变量声明必须一次性完成，且放在最前面, 否则mex编译错误
// 源文件名后缀为.cpp时，没有上面的问题，...- -||
double *pData;
mwSize i;
// 输入参数必须为一个，且为double类型
if ( nrhs != 1 || mxDOUBLE_CLASS != mxGetClassID(prhs[0]) ) {
mexErrMsgTxt( "输入参数不合法……" );
}
// 获取数据指针
pData = mxGetPr(prhs[0]);
// 遍历所有元素并打印到屏幕
for ( i = 0; i != mxGetNumberOfElements(prhs[0]); i++ ) {
displaySubscript( prhs[0], i );
mexPrintf( " = %g/n", pData[i] );
}
}
void displaySubscript( const mxArray *pArray, mwSize index ) {
// 源文件名后缀为.c时，所有变量声明必须一次性完成，且放在最前面, 否则mex编译错误
// 源文件名后缀为.cpp时，没有上面的问题，...- -||，代码好龊...
mwSize i, j;
mwSize numOfDim;
mwSize *subScript;
mwSize subIndex;
mwSize total;
const mwSize *Dims;
const char *className;
// 获取维度个数
numOfDim = mxGetNumberOfDimensions(pArray);
// 获取维度数组
Dims = mxGetDimensions(pArray);
// 获取类型名称
className = mxGetClassName(pArray);
// 分配下标数组内存
subScript = (mwSize *)mxCalloc( numOfDim, sizeof( mwSize ) );
// 根据当前的索引号生成下标
subIndex = index;
for ( i = numOfDim - 1; ; i-- ) {
total = 1;
for ( j = 0; j < i; j++ ) {
total *= Dims[j];
}
subScript[i] = subIndex / total;
subIndex = subIndex % total;
if ( 0 == i ) {
break;
}
}
// 打印出所有下标
mexPrintf( "(" );
for ( i = 0; i < numOfDim - 1; i++ ) {
mexPrintf( "%d,", subScript[i] + 1 );
}
mexPrintf( "%d)", subScript[numOfDim-1] + 1 );
// 释放下标数组内存
mxFree( subScript );
}
在Matlab使用mex命令编译源文件时，要注意这样一个现象：源文件名后缀为.c时，所有变量声明必须一次性完成，且放在最前面, 否则mex编译错误；而源文件名后缀为.cpp时，就没有上面的问题，...- -||。
实验结果
混合编程API一览
MX Matrix Library
mwIndex (C and Fortran) | Type for index values |
mwPointer (Fortran) | Pointer type for platform |
mwSignedIndex (C and Fortran) | Signed integer type for size values |
mwSize (C and Fortran) | Type for size values |
mxAddField (C and Fortran) | Field to structure array |
mxArray (C and Fortran) | Type for MATLAB array |
mxArrayToString (C) | Convert array to string |
mxAssert (C) | Check assertion value for debugging purposes |
mxAssertS (C) | Check assertion value without printing assertion text |
mxCalcSingleSubscript (C and Fortran) | Offset from first element to desired element |
mxCalloc (C and Fortran) | Allocate dynamic memory for array using MATLAB memory manager |
mxChar (C) | Type for string array |
mxClassID (C) | Enumerated value identifying class of array |
mxClassIDFromClassName (Fortran) | Identifier corresponding to class |
mxComplexity (C) | Flag specifying whether array has imaginary components |
mxCopyCharacterToPtr (Fortran) | CHARACTER values from Fortran array to pointer array |
mxCopyComplex16ToPtr (Fortran) | COMPLEX*16 values from Fortran array to pointer array |
mxCopyComplex8ToPtr (Fortran) | COMPLEX*8 values from Fortran array to pointer array |
mxCopyInteger1ToPtr (Fortran) | INTEGER*1 values from Fortran array to pointer array |
mxCopyInteger2ToPtr (Fortran) | INTEGER*2 values from Fortran array to pointer array |
mxCopyInteger4ToPtr (Fortran) | INTEGER*4 values from Fortran array to pointer array |
mxCopyPtrToCharacter (Fortran) | CHARACTER values from pointer array to Fortran array |
mxCopyPtrToComplex16 (Fortran) | COMPLEX*16 values from pointer array to Fortran array |
mxCopyPtrToComplex8 (Fortran) | COMPLEX*8 values from pointer array to Fortran array |
mxCopyPtrToInteger1 (Fortran) | INTEGER*1 values from pointer array to Fortran array |
mxCopyPtrToInteger2 (Fortran) | INTEGER*2 values from pointer array to Fortran array |
mxCopyPtrToInteger4 (Fortran) | INTEGER*4 values from pointer array to Fortran array |
mxCopyPtrToPtrArray (Fortran) | Pointer values from pointer array to Fortran array |
mxCopyPtrToReal4 (Fortran) | REAL*4 values from pointer array to Fortran array |
mxCopyPtrToReal8 (Fortran) | REAL*8 values from pointer array to Fortran array |
mxCopyReal4ToPtr (Fortran) | REAL*4 values from Fortran array to pointer array |
mxCopyReal8ToPtr (Fortran) | REAL*8 values from Fortran array to pointer array |
mxCreateCellArray (C and Fortran) | Unpopulated N-D cell array |
mxCreateCellMatrix (C and Fortran) | Unpopulated 2-D cell array |
mxCreateCharArray (C and Fortran) | Unpopulated N-D string array |
mxCreateCharMatrixFromStrings (C and Fortran) | Create populated 2-D string array |
mxCreateDoubleMatrix (C and Fortran) | 2-D, double-precision, floating-point array initialized to 0 |
mxCreateDoubleScalar (C and Fortran) | Scalar, double-precision array initialized to specified value |
mxCreateLogicalArray (C) | N-D logical array initialized to false |
mxCreateLogicalMatrix (C) | 2-D, logical array initialized to false |
mxCreateLogicalScalar (C) | Scalar, logical array |
mxCreateNumericArray (C and Fortran) | Unpopulated N-D numeric array |
mxCreateNumericMatrix (C and Fortran) | Numeric matrix initialized to 0 |
mxCreateSparse (C and Fortran) | 2-D unpopulated sparse array |
mxCreateSparseLogicalMatrix (C) | Unpopulated 2-D, sparse, logical array |
mxCreateString (C and Fortran) | Create 1-by-N array initialized to specified string |
mxCreateStructArray (C and Fortran) | Unpopulated N-D structure array |
mxCreateStructMatrix (C and Fortran) | Unpopulated 2-D structure array |
mxDestroyArray (C and Fortran) | Free dynamic memory allocated by MXCREATE* functions |
mxDuplicateArray (C and Fortran) | Make deep copy of array |
mxFree (C and Fortran) | Free dynamic memory allocated by MXCALLOC, MXMALLOC, or MXREALLOC functions |
mxGetCell (C and Fortran) | Contents of array cell |
mxGetChars (C) | Pointer to character array data |
mxGetClassID (C and Fortran) | Class of array |
mxGetClassName (C and Fortran) | Class of array as string |
mxGetData (C and Fortran) | Pointer to real data |
mxGetDimensions (C and Fortran) | Pointer to dimensions array |
mxGetElementSize (C and Fortran) | Number of bytes required to store each data element |
mxGetEps (C and Fortran) | Value of EPS |
mxGetField (C and Fortran) | Field value, given field name and index, into structure array |
mxGetFieldByNumber (C and Fortran) | Field value, given field number and index, into structure array |
mxGetFieldNameByNumber (C and Fortran) | Field name, given field number, in structure array |
mxGetFieldNumber (C and Fortran) | Field number, given field name, in structure array |
mxGetImagData (C and Fortran) | Pointer to imaginary data of array |
mxGetInf (C and Fortran) | Value of infinity |
mxGetIr (C and Fortran) | Sparse matrix IR array |
mxGetJc (C and Fortran) | Sparse matrix JC array |
mxGetLogicals (C) | Pointer to logical array data |
mxGetM (C and Fortran) | Number of rows in array |
mxGetN (C and Fortran) | Number of columns in array |
mxGetNaN (C and Fortran) | Value of NaN (Not-a-Number) |
mxGetNumberOfDimensions (C and Fortran) | Number of dimensions in array |
mxGetNumberOfElements (C and Fortran) | Number of elements in array |
mxGetNumberOfFields (C and Fortran) | Number of fields in structure array |
mxGetNzmax (C and Fortran) | Number of elements in IR, PR, and PI arrays |
mxGetPi (C and Fortran) | Imaginary data elements in array of type DOUBLE |
mxGetPr (C and Fortran) | Real data elements in array of type DOUBLE |
mxGetProperty (C and Fortran) | Value of public property of MATLAB object |
mxGetScalar (C and Fortran) | Real component of first data element in array |
mxGetString (C and Fortran) | String array to C-style string |
mxIsCell (C and Fortran) | Determine whether input is cell array |
mxIsChar (C and Fortran) | Determine whether input is string array |
mxIsClass (C and Fortran) | Determine whether array is member of specified class |
mxIsComplex (C and Fortran) | Determine whether data is complex |
mxIsDouble (C and Fortran) | Determine whether mxArray represents data as double-precision, floating-point numbers |
mxIsEmpty (C and Fortran) | Determine whether array is empty |
mxIsFinite (C and Fortran) | Determine whether input is finite |
mxIsFromGlobalWS (C and Fortran) | Determine whether array was copied from MATLAB global workspace |
mxIsInf (C and Fortran) | Determine whether input is infinite |
mxIsInt16 (C and Fortran) | Determine whether array represents data as signed 16-bit integers |
mxIsInt32 (C and Fortran) | Determine whether array represents data as signed 32-bit integers |
mxIsInt64 (C and Fortran) | Determine whether array represents data as signed 64-bit integers |
mxIsInt8 (C and Fortran) | Determine whether array represents data as signed 8-bit integers |
mxIsLogical (C and Fortran) | Determine whether array is of type mxLogical |
mxIsLogicalScalar (C) | Determine whether scalar array is of type mxLogical |
mxIsLogicalScalarTrue (C) | Determine whether scalar array of type mxLogical is true |
mxIsNaN (C and Fortran) | Determine whether input is NaN (Not-a-Number) |
mxIsNumeric (C and Fortran) | Determine whether array is numeric |
mxIsSingle (C and Fortran) | Determine whether array represents data as single-precision, floating-point numbers |
mxIsSparse (C and Fortran) | Determine whether input is sparse array |
mxIsStruct (C and Fortran) | Determine whether input is structure array |
mxIsUint16 (C and Fortran) | Determine whether array represents data as unsigned 16-bit integers |
mxIsUint32 (C and Fortran) | Determine whether array represents data as unsigned 32-bit integers |
mxIsUint64 (C and Fortran) | Determine whether array represents data as unsigned 64-bit integers |
mxIsUint8 (C and Fortran) | Determine whether array represents data as unsigned 8-bit integers |
mxLogical (C) | Type for logical array |
mxMalloc (C and Fortran) | Allocate dynamic memory using MATLAB memory manager |
mxRealloc (C and Fortran) | Reallocate dynamic memory using MATLAB memory manager |
mxRemoveField (C and Fortran) | Remove field from structure array |
mxSetCell (C and Fortran) | Value of one cell of array |
mxSetClassName (C) | Convert structure array to MATLAB object array |
mxSetData (C and Fortran) | Set pointer to data |
mxSetDimensions (C and Fortran) | Modify number of dimensions and size of each dimension |
mxSetField (C and Fortran) | Set structure array field, given structure field name and array index |
mxSetFieldByNumber (C and Fortran) | Set structure array field, given field number and index |
mxSetImagData (C and Fortran) | Imaginary data pointer for array |
mxSetIr (C and Fortran) | IR array of sparse array |
mxSetJc (C and Fortran) | JC array of sparse array |
mxSetM (C and Fortran) | Number of rows in array |
mxSetN (C and Fortran) | Set number of columns in array |
mxSetNzmax (C and Fortran) | Set storage space for nonzero elements |
mxSetPi (C and Fortran) | Set new imaginary data for array |
mxSetPr (C and Fortran) | Set new real data for array |
mxSetProperty (C and Fortran) | Set value of public property of MATLAB object |
MEX Library
mexAtExit (C and Fortran) | Register function to call when MEX-function cleared or MATLAB software terminates |
mexCallMATLAB (C and Fortran) | Call MATLAB function, user-defined function, or MEX-file |
mexCallMATLABWithTrap (C and Fortran) | Call MATLAB function, user-defined function, or MEX-file and capture error information |
mexErrMsgIdAndTxt (C and Fortran) | Display error message with identifier and return to MATLAB prompt |
mexErrMsgTxt (C and Fortran) | Display error message and return to MATLAB prompt |
mexEvalString (C and Fortran) | Execute MATLAB command in caller workspace |
mexEvalStringWithTrap (C and Fortran) | Execute MATLAB command in caller workspace and capture error information |
mexFunction (C and Fortran) | Entry point to C/C++ or Fortran MEX-file |
mexFunctionName (C and Fortran) | Name of current MEX-function |
mexGet (C) | Value of specified Handle Graphics property |
mexGetVariable (C and Fortran) | Copy of variable from specified workspace |
mexGetVariablePtr (C and Fortran) | Read-only pointer to variable from another workspace |
mexIsGlobal (C and Fortran) | Determine whether variable has global scope |
mexIsLocked (C and Fortran) | Determine whether MEX-file is locked |
mexLock (C and Fortran) | Prevent clearing MEX-file from memory |
mexMakeArrayPersistent (C and Fortran) | Make array persist after MEX-file completes |
mexMakeMemoryPersistent (C and Fortran) | Make memory allocated by MATLAB software persist after MEX-function completes |
mexPrintf (C and Fortran) | ANSI C PRINTF-style output routine |
mexPutVariable (C and Fortran) | Array from MEX-function into specified workspace |
mexSet (C) | Set value of specified Handle Graphics property |
mexSetTrapFlag (C and Fortran) | Control response of MEXCALLMATLAB to errors |
mexUnlock (C and Fortran) | Allow clearing MEX-file from memory |
mexWarnMsgIdAndTxt (C and Fortran) | Warning message with identifier |
mexWarnMsgTxt (C and Fortran) | Warning message |
