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Re: Transformation Rules

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  • Subject: [mg119722] Re: Transformation Rules
  • From: Bob Hanlon <hanlonr at>
  • Date: Sat, 18 Jun 2011 19:57:09 -0400 (EDT)
  • Reply-to: hanlonr at

data = RandomInteger[100, 10]

{3, 27, 71, 1, 84, 42, 80, 55, 95, 33}

data //. {s___, x_, e___} /; x <= Max[s] :> {s, e}

{3, 27, 71, 84, 95}

Bob Hanlon

---- Stefan Salanski <wutchamacallit27 at> wrote: 

Hey everyone, I found a sort of intro/tutorial notebook on my hard
drive that I must have downloaded a while ago.
"ProgrammingFundamentals.nb". I am not sure of the source, though the
author appears to be a Mr. Richard Gaylord.

"These notes form the basis of a series of lectures given by the
author, in which the fundamental principles underlying Mathematica's
programming language are discussed and illustrated with carefully
chosen examples. This is not a transcription of those lectures, but
the note set was used to create a set of transparencies which
Professor Gaylord showed and spoke about during his lectures. These
notes formed the basis for both a single 6 hour one-day lecture and a
series of four 90 minute lectures, delivered to professionals and to

I sent it to a friend and recommended that he look through and try out
some of the exercises to become more familiar with Mathematica. It was
written in a previous version of Mathematica (dunno which, just not
8), but still has a lot of great exercises to try out. (the only real
difference being the new implementation of RandomInteger and
RandomReal instead of Random[Integer] and Random[Real])

Anyway, I have gotten stumped on one of the Transformation Rule
exercises which I have restated below:

   Use a transformation rule to take a list of elements and return a
list of those elements that are greater than all of the preceding
elements in the list.

How can this be done with transformation rules?

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