问在C中有没有更好的方法来求函数的第n阶导数？

EN

double func(double x)
{
    // a mathematical expression representing a smooth curve 
    //returns the value of the function at x      
}

double nthderive(double (*f)(double),double x0,int n)
{   
   const double delta=1.0e-8;
   double x1=x0 - delta;
   double x2=x0 + delta;
   if(n==0) {
       return f(x0);
   }
   else {
       return (nthderive(f,x2,n-1)-nthderive(f,x1,n-1))/(2*delta);
   }
}