Re: I'll try again: oct and arrays

[Søren Hauberg]

ons, 29 12 2010 kl. 14:34 +0100, skrev Jesper Schmidt Hansen:
> I think the difference is due to the fact that there exists an
> overhead using the () operator (not inlined by the compiler I guess),
> which is not there when you access the variable elements directly. Is
> this correct? If so, how to overcome this overhead without first
> copying everything to a second simple double array?

I am unsure of why the () operator causes slow down. A simple solution
would be to do something like (untested code):

  const double *values = A.fortran_vec ();
  const int numel = A.numel ();
  double sum = 0;
  for (int k = 0; k < numel; k++)
    sum += values [k];

Søren