c++ - 为什么这个 MEX 函数会产生意想不到的结果？

Question

我正在学习这本书Accelerating MATLAB Performance和 page 394 ，这段代码是这样写的:

#include "mex.h"
void mexFunction (int nlhs,mxArray *plhs[],/*outputs*/
    int nrhs, const mxArray *prhs[])/*inputs*/
{
    const char *name = mexFunctionName();
    printf("s() called with %d inputs,%d outputs\n",name,nrhs,nlhs);
}  

根据书上所说，用命令mex hello.cpp构建MEX代码后，应该会产生如下结果:

>> hello
hello() called with 0 inputs, 0 outputs
>> hello(1,2,3)
hello() called with 3 inputs, 0 outputs
>> [a,b] = hello(1,2,3)
hello() called with 3 inputs, 2 outputs
One or more output arguments not assigned during call to "hello".  

但是当我在我的Win7x64机器上运行相同的代码时，结果如下:

>> mex hello.cpp
Building with 'Microsoft Visual C++ 2010'.
MEX completed successfully. 
>> hello
s() called with 2082650752 inputs,0 outputs
>> hello(1,2,3)
s() called with 2082650752 inputs,3 outputs
>> [a,b] = hello(1,2,3)
s() called with 2082650752 inputs,3 outputs
One or more output arguments not assigned during call to "hello".  

这些意外结果的原因是什么？

Answer 1

感谢您提醒我 - 这是本书编辑阶段输入的错字 - 正确的代码是 printf('%s() called...(即前导 % 被错误删除)。我将相应地更新勘误表。

我希望本书的其余部分对您有所帮助。如果你这样做，那么请post a positive comment on Amazon .