Re: [q-lang-users] Re: Newbie questions and comments

[Albert G. <Dr....@t-...>]

Tim Haynes wrote:
> Random datapoint: on my machine it took Q 28mins to do the takfp test
> listed there.

Did you use integer or floating point arithmetic? Here are two runs from 
my machine:

==> tak 30 20 10; stats
11
485 secs, 278308692 reductions, 133 cells

==> tak 30.0 20.0 10.0; stats
11.0
431 secs, 278308692 reductions, 133 cells

I'd guess that with machine integers the performance would be closer to 
that of Python. Not that this is a real option, since Q's integers are 
always bigints.

> (However, at least it did it in constant memory; my obvious implementation
> in Perl took 7mins but blew to 1.4Gb VSZ...)

Languages without tail call elimination suck. ;-) Q uses only 133 
expression cells (~3KB), so the memory requirements would be just what 
the interpreter needs for global data anyway...

Albert

-- 
Dr. Albert Gr"af
Dept. of Music-Informatics, University of Mainz, Germany
Email:  Dr....@t-..., ag...@mu...
WWW:    http://www.musikwissenschaft.uni-mainz.de/~ag