🚀 go-pugleaf

In article <DC9nCI.HH9@inesc.pt>, pjn@novabase.pt (Paulo Jorge Cardiga Nunes) writes:

|> I'm trying to built a simple(?) routine to calculate a number powered to
|> other. (X^Y)
|> Well, it's simple, you may think, but... Y is not an integer. It's a real!!
|> So as X, but problems are not in X, but in Y!!!

template< class T > 
T toThePowerOf( T x, T y)
{
  T lnX = log( x );  // compute ln(x)
  T ylnX = y * lnX;  // compute y*ln(x)     == ln(x^y)
  T xToY = exp(ylnX) // compute e^(ln(x^y)) == x^y

  return xToY;
}

This will work for any type T that has log(), operator*() and exp() 
functions defined for it.  This includes complex numbers (!) aswell 
as reals (be they user-defined concrete data types or built-in types
such as double and float).  

Hope this helps,
Pablo