Re: Sum
- To: mathgroup at smc.vnet.net
- Subject: [mg55211] Re: Sum
- From: bghiggins at ucdavis.edu
- Date: Thu, 17 Mar 2005 03:28:29 -0500 (EST)
- References: <d192qe$ng4$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
mjumbo, Sum has the attribute HoldAll, so its arguments are held in an unevaluated form. Simply wrap the first argument of Sum with Evalaute Sum[Evaluate[x], {k, 0, Infinity}] Cheers, Brian mjumbo wrote: > Can sombody explain me why > > Sum[Exp[- k], {k, 0, Infinity}] > > gives the correct result, while the following (imho equivalent) statements > > x = Exp[-k] > Sum[x, {k, 0, Infinity}] > > don't? What should I do to make it work? It is rather vexing to copy/paste long expressions instead of using short placeholders like x. > __________ > www.newmail.ru -- Íîâàÿ Ïî÷òà: âñå ïî-íîâîìó.