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Re: A better way to decimate a file??

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  • Subject: [mg21387] Re: A better way to decimate a file??
  • From: "Jordan Rosenthal" <jr at>
  • Date: Sat, 1 Jan 2000 20:54:45 -0500 (EST)
  • Organization: Georgia Institute of Technology, Atlanta GA, USA
  • References: <849j3v$> <84dmfv$> <84jorg$>
  • Sender: owner-wri-mathgroup at


Rob was using the word correctly, but you have to have the secret decoder
ring. :)

In the signal processing community, the word "decimate" is extremely common
and has come to mean retaining every M-th sample of a sequence:

     y[n]  = x[M*n]

Another word, "downsampling", is sometimes used for this operation as well
(although some definitions for "downsampling" require that the sequence be
lowpass filtered first).

I guess the word "decimate" can be considered technical jargon which, as you
pointed out, has strayed slightly from its original meaning.

- Jordan

"Ed McBride" <emcbride at> wrote in message
news:84jorg$e12 at
> > "Rob Peterson" <rob-piovere at> wrote in message
> > news:849j3v$pgm 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.
> Don't mean to be anal-retentive, but the English language is something I
> care about.  Decimate comes from the Latin, meaning literally to kill
> every tenth man, a punishment meted out to Roman Legions that showed
> cowardice, or something else regarded as unacceptable.  Yes, things were
> definitely tough back then, but the Romans did conquer most of the known
> world, so... Anyway, the word can be used loosely to mean inflict heavy
> casualties, but I think "killing" 15 out of 16 is a bit too much.  Ed
> McBride, P.E.

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