MathGroup Archive 1999

[Date Index] [Thread Index] [Author Index]

Search the Archive

A better way to decimate a file??

  • To: mathgroup at
  • Subject: [mg21350] A better way to decimate a file??
  • From: rob-piovere at (Rob Peterson)
  • Date: Tue, 28 Dec 1999 00:49:35 -0500 (EST)
  • Sender: owner-wri-mathgroup at

I start with a list y that I need to decimate (sp?).  I've looked thru
the book and the only list function I can find to dump list elements
is the Drop[] function.  But, the best I can do is get rid of half of
the elements at a time.  I want to decimate this list by 16, ie I want
to dump 15 of every 16 entries.  So, I dump half of them four times.
This seems to work but I figure the pros hanging in this group will
know a much more elegant way to do this.  I did this:

(* start with y as the list  and ly = Length[y]  *)

y2 = Drop[y, {1, ly, 2}]; ly2 = Length[y2]

y4 = Drop[y2, {1, ly2, 2}]; ly4 = Length[y4]

and so on

So how should it really be done?  I'd like to be able to decimate by
non-binary numbers too.

Thanks, Rob

  • Prev by Date: Fonts and WinNT
  • Next by Date: Re: Plus[listOfReal__]=1.
  • Previous by thread: Re: Fonts and WinNT
  • Next by thread: Re: A better way to decimate a file??