Matlab嵌入C++是很容易的,嵌入C++的matlab在保持易用性的同时,可以加快程序速度。嵌入的C++代码不能直接在matlab中断点调试,需要借助Visual Studio之类的工具进行调试。这篇博客主要以简单的demo导入,介绍如何在Matlab中嵌入C++程序。
一、Matlab嵌入C++代码
mex test.cpp -R2018a 来编译代码,编译完成后就可以直接在matlab中通过 output = test(input) 来调用了。
至于如何编写.cpp MexFunction,请尽情查阅Matlab帮助文档 doc mex 左侧点击 C Mex Function/API 就可以查看教程了。
这里粘贴一个Matlab给的demo示例:
/*==========================================================
* arrayProduct.c - example in MATLAB External Interfaces
*
* Multiplies an input scalar (multiplier)
* times a 1xN matrix (inMatrix)
* and outputs a 1xN matrix (outMatrix)
*
* The calling syntax is:
*
* outMatrix = arrayProduct(multiplier, inMatrix)
*
* This is a MEX-file for MATLAB.
* Copyright 2007-2012 The MathWorks, Inc.
*
*========================================================*/
#include "mex.h"
/* The computational routine */
void arrayProduct(double x, double *y, double *z, mwSize n)
{
mwSize i;
/* multiply each element y by x */
for (i=0; i<n; i++) {
z[i] = x * y[i];
}
}
/* The gateway function */
void mexFunction( int nlhs, mxArray *plhs[],
int nrhs, const mxArray *prhs[])
{
double multiplier; /* input scalar */
double *inMatrix; /* 1xN input matrix */
size_t ncols; /* size of matrix */
double *outMatrix; /* output matrix */
/* check for proper number of arguments */
if(nrhs!=2) {
mexErrMsgIdAndTxt("MyToolbox:arrayProduct:nrhs","Two inputs required.");
}
if(nlhs!=1) {
mexErrMsgIdAndTxt("MyToolbox:arrayProduct:nlhs","One output required.");
}
/* make sure the first input argument is scalar */
if( !mxIsDouble(prhs[0]) ||
mxIsComplex(prhs[0]) ||
mxGetNumberOfElements(prhs[0])!=1 ) {
mexErrMsgIdAndTxt("MyToolbox:arrayProduct:notScalar","Input multiplier must be a scalar.");
}
/* make sure the second input argument is type double */
if( !mxIsDouble(prhs[1]) ||
mxIsComplex(prhs[1])) {
mexErrMsgIdAndTxt("MyToolbox:arrayProduct:notDouble","Input matrix must be type double.");
}
/* check that number of rows in second input argument is 1 */
if(mxGetM(prhs[1])!=1) {
mexErrMsgIdAndTxt("MyToolbox:arrayProduct:notRowVector","Input must be a row vector.");
}
/* get the value of the scalar input */
multiplier = mxGetScalar(prhs[0]);
/* create a pointer to the real data in the input matrix */
#if MX_HAS_INTERLEAVED_COMPLEX
inMatrix = mxGetDoubles(prhs[1]);
#else
inMatrix = mxGetPr(prhs[1]);
#endif
/* get dimensions of the input matrix */
ncols = mxGetN(prhs[1]);
/* create the output matrix */
plhs[0] = mxCreateDoubleMatrix(1,(mwSize)ncols,mxREAL);
/* get a pointer to the real data in the output matrix */
#if MX_HAS_INTERLEAVED_COMPLEX
outMatrix = mxGetDoubles(plhs[0]);
#else
outMatrix = mxGetPr(plhs[0]);
#endif
/* call the computational routine */
arrayProduct(multiplier,inMatrix,outMatrix,(mwSize)ncols);
}
二、Matlab嵌入C++代码的调试
在windows平台下,借助Visual Studio进行调试。
1.首先点开Matlab,编译带调试信息的C++代码 mex test.cpp -g -R2018a。编译完成后不要关闭Matlab。
2.然后点开Visual Studio,调试->附加到进程,在弹出的对话框中选择Matlab进程。
3.然后VS中文件->打开->文件,然后选择test.cpp,就可以在里面打断点了(这时断点旁边有个小警告,可以忽略掉)
4.在Matlab中运行output = test(input) 命令,函数执行到cpp程序时,VS中就可以命中断点,进行调试了。