举例说明使用MATLAB Coder从MATLAB生成C/C++代码步骤
MATLAB Coder可以从MATLAB代码生成独立的、可读性强、可移植的C/C++代码。
使用MATLAB Coder产生代码的3个步骤:①准备用于产生代码的MATLAB算法;②检查MATLAB代码的兼容性(有些matlab代码语句并不能生成c/c++代码);③产生最终使用的源代码或MEX。
利用MATLAB Coder生成c++代码,并在vs2008中验证:
一个简单的例子,两数相乘:
1、安装matlab2011a或者更新版本;
2、简单生成一个foo.m文件;
function c = foo(a, b)%#codegen
%This function muliplies a and b
c = a * b
其中,%#codegen可以防止出现警告错误
3、在命令窗口,输入mex -setup,选中一个存在的编译器;
4、在命令窗口输入coder(图形界面),回车,弹出MATLAB Coder Project对话框;
5、在New选项卡Name中输入一个工程名foo.prj;点击Ok,弹出MATLAB Coder MEX Function对话框;
6、在Overview选项卡中,点击Add files,弹出对话框,选中foo.m打开;
7、单击变量a,选择Define by Example…,弹出MATLAB Coder Define by Example对话框,在MATLAB Expression中输入5,点击OK;同样变量b也进行相应操作,输入6;
8、选中Build选项卡,Output type中选择c/c++ Static Library;选中Generate code only;
9、点击More settings,GeneralàLanguage选择C++;Interface选项中去掉所有选项;Close;
10、点击Build,进行编译;点击View report,弹出Code Generation Report对话框,此时,变量a、b、c会显示相应的变量信息;
11、利用vs2008建立一个控制台应用程序,将生成的相关文件foo.h、foo.cpp、rtwtypes.h、foo_types.h拷到相关目录下并添加到应用程序中;
12、在foo.cpp文件中添加#include “stdafx.h”;//VC++6.0找不到这个库,实际测试时,忽略
13、test.cpp文件中代码为: //自行编写的一个测试文件
//#include "stdafx.h" //忽略
#include "foo.h"
#include
using namespace std;
int _tmain(int argc, _TCHAR* argv[]) //实际测试时改为 main()
{
double a = 0.0, b = 0.0, c = 0.0;
cin>>a>>b;
c = foo(a, b);
cout<<"c = "<
return 0;
}
一个复杂的例子,求一个数的n次方根:
1、 两个.m文件:
nrt.m:
function [nth_rt, iterations, hstry] = nrt(varargin)%#codegen
%This function will use a Newton Search Technique to find
%the nth root of a number, a, to the tolerance, tol.
%The square root
% nrt(10, 2), or nrt(10, 2, 1e-9)
%The "n" root
%nrt(10, n), or nrt(10, n, 1e-9)
a = varargin{1};
n = varargin{2};
if nargin ~= 3
tol = 1e-9;
else
tol = varargin{3};
end
if a < 0
nth_rt = 0;
iterations = 0;
hstry = 0;
else
[nth_rt, hstry] = newtonSearchAlgorithm(a, n, tol);
iterations = length(find(hstry ~= 0));
%iterations = sum(hstry ~= 0);
end
newtonSearchAlgorithm.m:
function [x, h] = newtonSearchAlgorithm(b, n, tol) %#codegen
%Given, "a", this function finds the nth root of a
%number by finding where: x^n-a = 0
coder.inline('never'); %使其生成一个单独的c++文件
notDone = 1;
aNew = 0; %Refined Guess Initialization
a = 1; %Initial Guess
cnt = 0;
h = zeros(50, 1);
h(1) = a;
while notDone
cnt = cnt + 1;
[curVal, slope] = f_and_df(a, b, n); % square
yint = curVal - slope * a;
aNew = -yint / slope; %The new guess
h(cnt) = aNew;
if (abs(aNew-a) < tol) %Break if it's converged
notDone = 0;
elseif cnt > 49 �ter 50 iterations, stop
notDone = 0;
aNew = 0;
else
a = aNew;
end
end
x = aNew;
function [f, df] = f_and_df(a, b, n)
%Our function is f=a^n-b and it's derivative is n*a^(n-1).
f = a^n-b;
df = n*a^(n-1);
2、 在命令窗口输入coder(图形界面),回车,弹出MATLAB Coder Project对话框;
3、在New选项卡Name中输入一个工程名nrt.prj;点击Ok,弹出MATLAB Coder MEX Function对话框;
4、在Overview选项卡中,点击Add files,弹出对话框,选中nrt.m打开;
5、添加三个输入,分别为10、2、1e-9;两个输入也可以;
6、选中Build选项卡,Output type中选择c/c++ Static Library;选中Generate code only;
7、点击More settings,GeneralàLanguage选择C++;Interface选项中去掉所有选项;Close;
8、点击Build,进行编译;点击View report,弹出Code Generation Report对话框;
9、利用vs2008建立一个控制台应用程序,将生成的相关文件nrt.cpp、nrt.h、newtonSearchAlgorithm.cpp、newtonSearchAlgorithm.h、nrt_types.h、rtwtypes.h拷到相关目录下并添加到应用程序中;
10、分别在nrt.cpp、newtonSearchAlgorithm.cpp文件中添加#include “stdafx.h”;
11、test.cpp文件中代码为:
#include "stdafx.h"
#include "nrt.h"
#include
using namespace std;
int _tmain(int argc, _TCHAR* argv[])
{
double varargin_1 = 0, varargin_2 = 0, varargin_3 = 1e-9;
cin>>varargin_1>>varargin_2;
double nth_rt = 0, iterations = 0;
double hstry_data[50] = {0};
int hstry_sizes[1] = {0};
nrt(varargin_1, varargin_2, varargin_3, &nth_rt, &iterations, hstry_data, hstry_sizes);
cout<<"nth_rt = "<
cout<<"iterations = "<
cout<<"hstry_data = "<
for (int i=0; i<50; i++)
{
cout<
}
cout<<"hstry_sizes = "<
return 0;
}