[Matlab] matlab与C/C++混合编程汇总

matlab 与外部程序的编程接口两大类：

               一是 如何在matlab里调用其他语言写的代码。 （见例子：使用C-MEX技术，ActiveX技术）

               二是 如何在其他语言里调用matlab。 （见 使用matlab引擎, MAT数据交换, matlab发布com组件, DeployTool）

matlab接口技术包含以下几个方面：

1. 数据导入导出，主要是MAT文件数据的导入导出。

2.普通的动态链接库dll文件的交互，Matlab6.5起，直接matlab环境中调用dll文件导出的函数。

3.matlab环境中调用c/c++语言代码的接口，通过MEX（MATLAB EXecutable）技术实现。C/C++代码通过实现特殊的入口函数，编译成MEX文件（实际dll），可以像一般的m文件被调用，调用级别比M函数高。

4.matlab环境中调用java，6.0版本起，matlab增加java支持，其工作界面GUI也是java编写的，且包含了Java虚拟机。

5.对COM与DDE的支持，5.1后DDE没再增加新内容，6.5后推荐COM接口。matlab的com编译器能将matlab函数转换成COM对象供多种语言使用。

6.matlab使用网络服务或者和串口通讯。

使用matlab引擎

前段客户端使用 matlab引擎(matlab的一组接口函数engXXXX) 与后台启动的matlab进程 进行数据交换和命令的传送。

几乎可以利用matlab的全部功能，但需要计算机上安装matlab软件，执行效率低，不宜用于商业应用软件。

VC++ 开发环境，需要添加Include:  {matlab安装目录}\extern\include\         Library Files: {matlab安装目录}\extern\lib\win32\microsoft\

C and Fortran Engine Library Functions

engOpen (C and Fortran)	Start MATLAB engine session
engOpenSingleUse (C)	Start MATLAB engine session for single, nonshared use
engClose (C and Fortran)	Quit MATLAB engine session
Engine (C)	Type for MATLAB engine
engEvalString (C and Fortran)	Evaluate expression in string
engGetVariable (C and Fortran)	Copy variable from MATLAB engine workspace
engPutVariable (C and Fortran)	Put variable into MATLAB engine workspace
engGetVisible (C)	Determine visibility of MATLAB engine session
engSetVisible (C)	Show or hide MATLAB engine session
engOutputBuffer (C and Fortran)	Specify buffer for MATLAB output

engPutArray 和 engGetArray 已过时，被engPutVariable 和 engGetVariable取替，但仍可使用。

        mxArray * T = mxCreateDoubleMatrix(1, 10, mxREAL);
	memcpy((char *) mxGetPr(T), (char *) time, 10*sizeof(double));

	/*
	 * Place the variable T into the MATLAB workspace
	 */
	engPutVariable(ep, "T", T);

	/*
	 * Evaluate a function of time, distance = (1/2)g.*t.^2
	 * (g is the acceleration due to gravity)
	 */
	engEvalString(ep, "D = .5.*(-9.8).*T.^2;");

	 /*
	 * Use engOutputBuffer to capture MATLAB output. Ensure first that
	 * the buffer is always NULL terminated.
	 */
	 buffer[BUFSIZE] = '\0';
	 engOutputBuffer(ep, buffer, BUFSIZE);

	 /*
	 * the evaluate string returns the result into the
	 * output buffer.
	 */
	 engEvalString(ep, "whos");
	 MessageBox ((HWND)NULL, (LPSTR)buffer, (LPSTR) "MATLAB - whos", MB_OK);

完整项目：demo1

MAT数据交换

 MATLAB中操作MAT文件命令 load ， save

 

 windows系统中可以使用type查看mat文件的版本等信息。

>> type mattest.mat

MATLAB 5.0 MAT-file, Platform: PCWIN, Created on: Mon May 30 13:55:35 2016       

C and Fortran MAT-File Library Functions

matOpen (C and Fortran)	Open MAT-file
matClose (C and Fortran)	Close MAT-file
MATFile (C and Fortran)	Type for MAT-file
matGetVariable (C and Fortran)	Array from MAT-file
matGetVariableInfo (C and Fortran)	Array header information only
matGetNextVariable (C and Fortran)	Next array in MAT-file
matGetNextVariableInfo (C and Fortran)	Array header information only
matPutVariable (C and Fortran)	Array to MAT-file
matPutVariableAsGlobal (C and Fortran)	Array to MAT-file as originating from global workspace
matDeleteVariable (C and Fortran)	Delete array from MAT-file
matGetDir (C and Fortran)	List of variables in MAT-file
matGetFp (C)	File pointer to MAT-file
mxIsFromGlobalWS (C and Fortran)	Determine whether array was copied from MATLAB global workspace

	pmat = matOpen(file,"r");
	if (NULL == pmat){	
		sprintf(buf, "打开文件错误 %s",file);
		MessageBox(buf);
		return;	
	}

	m_list.AddString("打开文件");

	/** read in each array we just wrote **/
	pa1 = matGetVariable(pmat,"LocalDouble");
	if(NULL == pa1){
		MessageBox("读取 matrix LocalDouble failed");
		return;
	}
	m_list.AddString("读取matix LocalDouble");

	if(mxGetNumberOfDimensions(pa1) != 2){
		MessageBox("矩阵保存错误：结果不是两维!");
		return;
	}
	m_list.AddString("矩阵是两维的");

	pa2 = matGetVariable(pmat,"GlobalDouble");
	if(NULL == pa2){
		MessageBox("读取 matrix GlobalDouble failed");
		return;
	}
	m_list.AddString("读取GlobalDouble");

	if( !(mxIsFromGlobalWS(pa2)) ) {
		MessageBox("全局保存错误，GlobalDouble不是全局的");
	}
	m_list.AddString("GlobalDouble是全局的");

	pa3 = matGetVariable(pmat,"LocalString");
	if(NULL == pa3){
		MessageBox("读取LocalString错误");
		return;
	}
	m_list.AddString("读取LocalString");

	status = mxGetString(pa3, str, sizeof(str));
	if( 0 != status){
		MessageBox("空间不足");
			return;
	}
	if( strcmp(str,"MATLAB: the language of technical computing") ){
		MessageBox("字符串保存错误");
	}
        m_list.AddString("字符串保存完整");

	/** clean up before exit **/
	mxDestroyArray(pa1);
	mxDestroyArray(pa2);
	mxDestroyArray(pa3);

	if(matClose(pmat) != 0){
		sprintf(buf, "",file);
		MessageBox(buf);
		return;
	}
	m_list.AddString("关闭文件");

完整项目： demo2

使用C-MEX技术

对于影响matlab执行速度的for、while等循环，可以编写相应的C/Fortan子函数,编译成MEX文件，提高运行速度。

对于一些访问硬件的底层操作，A/D、D/A或者中断，可以通过MEX直接访问，克服matlab不足。

matlab编程效率高，尽量使用maltab编程，对于耗时或者功能受限的部分采用mex编程。

windows里需要对mex编译器进行配置编译

>> mex -setup

please choose your compiler for building external interface(MEX) files:

Would you like mex to locate installed compilers[y]/n?

按照提示选择对应的编译器，最终生成mexopts.bat

C MEX Library Functions

mexFunction	Entry point to C/C++ or Fortran MEX file
mexFunctionName	Name of current MEX function
mexAtExit	Register function to call when MEX function clears or MATLAB terminates

mexCallMATLAB	Call MATLAB function, user-defined function, or MEX file
mexCallMATLABWithTrap	Call MATLAB function, user-defined function, or MEX-file and capture error information
mexEvalString	Execute MATLAB command in caller workspace
mexEvalStringWithTrap	Execute MATLAB command in caller workspace and capture error information

mexGet	Value of specified graphics property
mexSet	Set value of specified graphics property
mexGetVariable	Copy of variable from specified workspace
mexGetVariablePtr	Read-only pointer to variable from another workspace
mexPutVariable	Array from MEX-function into specified workspace

mexPrintf

ANSI C PRINTF-style output routine

mexSetTrapFlag	Control response of MEXCALLMATLAB to errors
mexErrMsgIdAndTxt	Display error message with identifier and return to MATLAB prompt
mexWarnMsgIdAndTxt	Warning message with identifier
mexErrMsgTxt	Display error message and return to MATLAB prompt
mexWarnMsgTxt	Warning message

mexIsLocked	Determine if MEX-file is locked
mexLock	Prevent clearing MEX-file from memory
mexUnlock	Allow clearing MEX-file from memory
mexMakeArrayPersistent	Make array persist after MEX file completes
mexMakeMemoryPersistent	Make memory allocated by MATLAB software persist after MEX-function completes

入口函数：

C Syntax

#include "mex.h"
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, 
  const mxArray *prhs[])

Fortran Syntax

#include "fintrf.h"
subroutine mexFunction(nlhs, plhs, nrhs, prhs)
integer nlhs, nrhs
mwPointer plhs(*), prhs(*)

Arguments

nlhs

Number of expected output mxArrays

plhs

Array of pointers to the expected output mxArrays

nrhs

Number of input mxArrays

prhs

Array of pointers to the input mxArrays. Do not modify any prhs values in your MEX file. 

/*=================================================================
 * mexfunction.c 
 *
 * This example demonstrates how to use mexFunction.  It returns
 * the number of elements for each input argument, providing the 
 * function is called with the same number of output arguments
 * as input arguments.
 
 * This is a MEX-file for MATLAB.  
 * Copyright 1984-2006 The MathWorks, Inc.
 * All rights reserved.
 *=================================================================*/
/* $Revision: 1.5.6.2 $ */
#include "mex.h"
#pragma comment(lib,"libmx.lib")
//#pragma comment(lib,"libmat.lib")
#pragma comment(lib,"libmex.lib")

void
mexFunction(int nlhs,mxArray *plhs[],int nrhs,const mxArray *prhs[])
{
    int        i;
       
    /* Examine input (right-hand-side) arguments. */
    mexPrintf("\nThere are %d right-hand-side argument(s).", nrhs);
    for (i=0; i nrhs)
      mexErrMsgTxt("Cannot specify more outputs than inputs.\n");
    for (i=0; i

matlab发布com组件

matlab com builder技术，把matlab开发的算法做成组件，这些独立的com对象独立于matlab的环境。

实际上com生成过程是通过matlab的c语言编译器mcc生成，mcc和mbuild命令完全实现了matlab com builder的全部功能。

使用mbuild -setup 加载安装了的编译器

然后使用deploytool （图像界面的deployment tool)选择matlab builder for .Net 选择 Generic COM component

然后往工程中加入需要的M文件或者MEX文件。

通过工具tools/build  (ctrl +B) 编译生成相应的idl 和 代码。（实际调用了mcc命令）

再通过tools/package (ctrl +P)发布com文件。

示例1 ： include _idl.h 和 idl_i.c 文件

	VARIANT x,y,out1;

	HRESULT hr = CoInitialize(NULL);

	ICOMDemo1 *pImycomponentclass;
	hr = CoCreateInstance( CLSID_COMDemo1, NULL, CLSCTX_INPROC_SERVER, IID_ICOMDemo1, (void **)& pImycomponentclass);

	//
	x.vt = VT_R8;
	y.vt = VT_R8;
	
	x.dblVal = m_mul1;
	y.dblVal = m_mul2;
	//
	hr = (pImycomponentclass -> multidouble(1, &out1, x, y));
	m_result = out1.dblVal;
	//
	CoUninitialize();

完整项目:  demo3

示例2:    使用import "xxx.dll" raw_interfaces_only no_namespace named_guids (自动生成.tlh文件)

	HRESULT hr = CoInitialize(NULL);

	VARIANT x, y, out1;
	try{
		ICOMDemo1Ptr pImycomponentclass;
		hr = pImycomponentclass.CreateInstance(OLESTR("COMDemo1.COMDemo1.1_0"));
		if(FAILED(hr))  _com_issue_error(hr);

		x.vt = VT_R8;
		y.vt = VT_R8;
		x.dblVal = m_mul1;
		y.dblVal = m_mul2;

		hr = (pImycomponentclass -> multidouble(1,&out1,x,y));
		m_result = out1.dblVal;
	}catch(_com_error & e)
	{
		MessageBox( e.Description().length() != 0 ? (LPCSTR) e.Description(): e.ErrorMessage());
	}
	
	//
	CoUninitialize();

完整项目： demo4

示例3:    使用后期绑定com组件

	//
	VARIANT x, y, out1;
	//
	HRESULT hr = CoInitialize(NULL);
	//
	XYDispDriver disp;
	bool res = disp.CreateObject("COMDemo1.COMDemo1");
	if (false == res) return;

	x.vt = VT_R8;
	y.vt = VT_R8;
	x.dblVal = m_mul1;
	y.dblVal = m_mul2;
	//
	disp.InvokeMethod("multidouble",1, &out1, x, y);
	m_result = out1.dblVal ;
	//
	CoUninitialize();

完整项目：http://download.csdn.net/detail/fonjames/9537997

DeployTool (C++ shared library or standalone application)

mcc -W cpplib:YYYXXXXX  -T link:lib XXXXXX.m

或者直接deployTool中选择exported function (m 文件）

依赖于mclmcrrt.lib

C/C++ API

mclmcrInitialize	Initializes the MATLAB Runtime proxy library
mclInitializeApplication	Set up application state shared by all MATLAB Runtime instances created in current process
mclTerminateApplication	Close MATLAB Runtime-internal application state
Initialize[WithHandlers]	Initialize MATLAB Runtime instance associated with library
Terminate	Free all resources allocated by MATLAB Runtime instance associated with library

mwArray	Class used to pass input/output arguments to C functions generated by MATLAB Compiler SDK
mwException	Exception type used by the mwArray API and the C++ interface functions
mwString	String class used by the mwArray API to pass string data as output from certain methods

mclRunMain	Mechanism for creating identical wrapper code across all platforms
mclIsMCRInitialized	Determine if MATLAB Runtime has been properly initialized
mclWaitForFiguresToDie	Enable deployed applications to process graphics events, enabling figure windows to remain displayed
mclGetLastErrorMessage	Last error message from unsuccessful function call
mclGetLogFileName	Retrieve name of log file used by MATLAB Runtime
mclIsJVMEnabled	Determine if MATLAB Runtime was launched with instance of Java Virtual Machine (JVM)
mclIsNoDisplaySet	Determine if -nodisplay mode is enabled

示例1： http://download.csdn.net/detail/fonjames/9538010

	bool res = false;
	res = mclInitializeApplication(NULL,0);
	if(!res) MessageBox("初始化Application错误!");
	res = libmccdemo1Initialize();
	if(!res) MessageBox("初始化Lib错误!");
---
	mccdemo1();
	mclWaitForFiguresToDie(NULL);
---
	res = mclTerminateApplication();
	if(!res) MessageBox("结束程序错误!");
	libmccdemo1Terminate();

示例2： http://download.csdn.net/detail/fonjames/9538014

	// TODO: Add extra initialization here
	bool res = false;
	res = mclInitializeApplication(NULL,0);
	if(!res) MessageBox("初始化Application错误");
	res = libmccdemo2Initialize();
	if(!res) MessageBox("初始化Lib错误!");
------
	// TODO: Add your control notification handler code here
	double figsize[] = {0.0 , 0.0};
	//
	CRect client_rect;
	GetClientRect(&client_rect);
	figsize[0] = client_rect.Width();
	figsize[1] = client_rect.Height();

	//
	mwArray mwFigSize(2,1,  mxDOUBLE_CLASS, mxREAL);
	mwFigSize.SetData(figsize,2);

	//call fun
	mccdemo2(mwFigSize);

	//
	m_figure.PasteFigure();
----
	// TODO: Add your message handler code here
	bool res = mclTerminateApplication();
	if (!res) MessageBox ("结束程序错误");
	libmccdemo2Terminate();

示例3:   http://download.csdn.net/detail/fonjames/9538020

	// TODO: Add extra initialization here
	bool res = false;
	res = mclInitializeApplication(NULL,0);
	if (!res) MessageBox("初始化Application错误!");
	res = libmccdemo3Initialize();
	if (!res) MessageBox("初始化Lib错误!");
-----
	char wnd_name[] = "MyTest";

	mwArray mwWndName(wnd_name);
	mccdemo3(mwWndName);
	
	HWND hFig = ::FindWindow(NULL,wnd_name);
	while( hFig == NULL) hFig = ::FindWindow(NULL,wnd_name);
	::ShowWindow(hFig, SW_HIDE);

	CRect figure_rt;
	CWnd *myfigure = GetDlgItem(IDC_STATIC);
	myfigure->GetWindowRect(&figure_rt);
	long fig_w = figure_rt.Width();
	long fig_h = figure_rt.Height();

	::SetParent(hFig,myfigure->GetSafeHwnd());
	
	long lStyle = ::GetWindowLong(hFig,GWL_STYLE);
	::SetWindowLong(hFig, GWL_STYLE,lStyle &(~ WS_CAPTION) & (~ WS_THICKFRAME));
	::ShowWindow(hFig, SW_SHOW);

	::SetWindowPos(hFig, NULL, 0,0, fig_w+8, fig_h +33, SWP_NOZORDER|SWP_NOACTIVATE);
	::ShowWindow(hFig, SW_SHOW);

	::SetForegroundWindow(this -> m_hWnd);
----
	bool res = mclTerminateApplication();
	if(!res) MessageBox("Terminate failed");
	libmccdemo3Terminate();

使用ActiveX技术

1. matlab作为activeX自动服务器，在VC中 开启progid  “MATLAB.Application", 然后通过invoke调用matlab的函数完成计算。

	HRESULT hr;
	wchar_t progid[] = L"Matlab.Application";
	CLSID clsid;
	::CLSIDFromProgID(progid, &clsid);
	IDispatch* pIDdispatch = NULL;

	::CoCreateInstance(clsid, NULL, CLSCTX_LOCAL_SERVER, IID_IDispatch, (void**)&pIDdispatch);

	DISPID dispid;
	OLECHAR *name = L"Execute";
	pIDdispatch -> GetIDsOfNames(IID_NULL, &name, 1 , GetUserDefaultLCID(), &dispid);
	DISPPARAMS dispparams = { NULL, NULL, 1, 0};
	
	VARIANT para;
	para.vt = VT_BSTR;
	para.bstrVal = A2BSTR(m_Command.GetBuffer(512));

	VARIANT result;
	dispparams.rgvarg = ¶
	hr = pIDdispatch ->Invoke(dispid, //DISPID
		IID_NULL, //must be iid_null
		GetUserDefaultLCID(), DISPATCH_METHOD, //method
		&dispparams, //methods arguments
		&result, //results
		NULL, //exception
		NULL);//arguments error
	m_result = result.bstrVal;

完整代码： http://download.csdn.net/detail/fonjames/9538024

2. matlab中使用actxserver("progid"), matlab实例化其他程序，比如excel之类的。

一些基本操作API（array）

Create array of specified type, allocate and free memory

Use the mxCreate* functions to create MATLAB® arrays. Use the mxCalloc, mxMalloc, and mxRealloc functions to allocate dynamic memory.

You allocate memory whenever you use an mxCreate* function or when you call the mxCalloc and associated functions. Use mxDestroyArray to free memory allocated by the mxCreate* functions. Use mxFree to free memory allocated by the mxCalloc and associated functions.

C Functions

mxCreateDoubleMatrix	2-D, double-precision, floating-point array
mxCreateDoubleScalar	Scalar, double-precision array initialized to specified value
mxCreateNumericMatrix	2-D numeric matrix
mxCreateNumericArray	N-D numeric array
mxCreateUninitNumericMatrix	Uninitialized 2-D numeric matrix
mxCreateUninitNumericArray	Uninitialized N-D numeric array

mxCreateString	1-N array initialized to specified string
mxCreateCharMatrixFromStrings	2-D mxChar array initialized to specified value
mxCreateCharArray	N-D mxChar array

mxCreateLogicalScalar	Scalar, logical array
mxCreateLogicalMatrix	2-D logical array
mxCreateLogicalArray	N-D logical array
mxCreateSparseLogicalMatrix	2-D, sparse, logical array

mxCreateSparse	2-D sparse array
mxCreateSparseLogicalMatrix	2-D, sparse, logical array

mxCreateStructMatrix	2-D structure array
mxCreateStructArray	N-D structure array

mxCreateCellMatrix	2-D cell array
mxCreateCellArray	N-D cell array

mxDestroyArray	Free dynamic memory allocated by MXCREATE* functions
mxDuplicateArray	Make deep copy of array

mxCalloc	Allocate dynamic memory for array, initialized to 0, using MATLAB memory manager
mxMalloc	Allocate uninitialized dynamic memory using MATLAB memory manager
mxRealloc	Reallocate dynamic memory using MATLAB memory manager
mxFree	Free dynamic memory allocated by mxCalloc, mxMalloc, mxRealloc, mxArrayToString, or mxArrayToUTF8String functions