求助 MATLAB 接口编程

C函数代码
/*
*fact.c - returns the factorial of a nonnegative integer.
*
*MATLAB usage: p=fact(n)
*
*Mastering MATLAB 7 C MEX Example 1
*/

#include "mex.h"

void mexFunction( int nlhs,       mxArray *plhs[],
          int nrhs, const mxArray *prhs[] )
{
    double n, j, *p;
    int i;

    n=mxGetScalar(prhs[0]);
    plhs[0]=mxCreateDoubleMatrix(1.1,mxREAL);
    p=mxGetPr(plhs[0]);

    j=1.0;
    for (i=n;i>1;i--)
    j=j*i;
    *p=j;
}
当在matlab 中运行 mex fact.c 时出现下面的错误提示
fact.c(18) : warning C4244: 'function' : conversion from 'const double ' to 'int ', possible loss of data
fact.c(18) : error C2198: 'mxCreateDoubleMatrix_700' : too few actual parameters
fact.c(22) : warning C4244: '=' : conversion from 'double ' to 'int ', possible loss of data
不胜感激！h