Alternating Sums
- To: mathgroup at christensen.cybernetics.net
- Subject: [mg340] Alternating Sums
- From: Xah Y Lee <xyl10060 at fhda.edu>
- Date: Mon, 19 Dec 1994 07:06:27 -0800 (PST)
This message is supposed to go to Jack Goldberg. I lost his email address.
Subject: Ways to construct alternating sums in mma.
Hi Jack. You may find the following code to construct mylist useful for
testing purposes.
mylist =
Table[
ToExpression@StringJoin["a", ToString[i]], {i,1 , 12 }
]
I think the simplist is
- Sum[ (-1)^i mylist[[i]], {i,1, Length[mylist]} ]
I made a study of all the contributions so far. I am amazed that the one
using Fold is fastest.
Xah Lee
xyl10060 at tiptoe.fhda.edu
Mountain View, CA.