Use of Sequence to strip "List"
- To: mathgroup at christensen.cybernetics.net
- Subject: [mg299] Use of Sequence to strip "List"
- From: mcdonald at delphi.umd.edu (William MacDonald)
- Date: Wed, 7 Dec 94 11:53:45 EST
Subject: Re: [mg281] Taking brackets off lists
To: <@comlab.oxford.ac.uk:corcoran at markov.stats (corcoran)
Date: Wed, 7 Dec 94 11:27:30 EST
In-Reply-To: <9412050724.AA29593 at christensen.cybernetics.net.; from "corcoran" at Dec 4, 94 5:56 pm
X-Mailer: ELM [version 2.3 PL11]
If I have a list like,
list = {1,1,1,2}
how do I find the part of a expression at the level specified by the list?
i.e.
I want exp[[1,1,1,2]],
but exp[[list]] doesn't work.
Thanks,
Stephen
Use
exp[[Apply[Sequence,list]]]
Sequence is an undocumented object mentioned by Roman Maeder which is
a "nude" list, that is, an ordered set with no delimiters.
--
William M. MacDonald
Professor of Physics
University of Maryland
Internet: mcdonald at delphi.umd.edu