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Re: simple set operations

  • To: mathgroup at
  • Subject: [mg57669] Re: [mg57635] simple set operations
  • From: "David Annetts" <davidannetts at>
  • Date: Fri, 3 Jun 2005 05:34:32 -0400 (EDT)
  • Sender: owner-wri-mathgroup at

Hi Edward,

> I'm hesitant to ask these questions (because they are so 
> simple) but after a
> 15 minute search through the docs I'm getting nowhere, so here goes:
>     1) what's the easiest way to generate a list of elements? ie:
> 	'a' .. 'h' == { a,b,c,d,e,f,g,h }
>     2) Is there a quick way to check whether an element is in a set?
> 	if ('a' == (any('a','b','c','d')) { print "a is in a,b,c,d"; }
> The first one I see could possibly be done by 'Array', but I 
> don't see how - the '#' refers to the generation of numbers, 
> but there seems to be no corresponding 'letter' symbol.
> As for #2, the easiest way would be through an overloading of 
> the '==' operator,
> but again, that doesn't seem to work..

(1) you need 
	lst = CharacterRange["a", "h"];

I'd suggest looking for it by typing ?*Range*.  Of the choices, pick the
most obvious.

(2) depending on what you want to do, any of 
	Cases[lst, "a"]
	Position[lst, "a"]
	MemberQ[lst, "a"]

Will give you something to work with, although the last might be the "best".
Any of these pop right out of the documentation.

This is not C++.  Rather than a "15 minute search", I suggest a longer, more
detailed examination during which you might learn some Mathematica syntax
and some simple functions.



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