[BUG] weird Zeta function

[parisse]

Zeta(n) is left as is if n>0 is odd, and computed using bernoulli numbers if n is even. You can't do any better if you want an exact answer. Of course, you can enter Zeta(d) where d is a floating point number to get an approximation.

Code:


...
    if ( (x.type==_INT_)){
      int n=x.val;
      if (!n)
    return minus_one_half;
      if (n==1)
    return plus_inf;
      if (n<0){
    if (n%2)
      return -rdiv(bernoulli(1-n),(1-n),contextptr) ;
    else
      return zero;
      }
      if (n%2)
    return symbolic(at_Zeta,x);
      else
    return pow(cst_pi,n)*ratnormal(abs(bernoulli(x),contextptr)*rdiv(pow(plus_two,n-1),factorial(n),contextptr));
    }
...