Re: Conditonal sum
- To: mathgroup at smc.vnet.net
- Subject: [mg50285] Re: [mg50263] Conditonal sum
- From: "Wolf, Hartmut" <Hartmut.Wolf at t-systems.com>
- Date: Tue, 24 Aug 2004 06:22:36 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
>-----Original Message----- >From: Christopher Grinde [mailto:christopher.grinde at hive.no] To: mathgroup at smc.vnet.net >Sent: Monday, August 23, 2004 12:35 PM >To: mathgroup at smc.vnet.net >Subject: [mg50285] [mg50263] Conditonal sum > > >I am new to mathematica and could really need a tip on how to >implement a >conditional sum. Pseudocode would be something like this > > >EndSum=a; >if j in Sm: > EndSum=EndSum+f[j] >end > > >I have tried doing this by using an If-clause inside the >sum-function, but > >this seems little elegant and is nor very suitable for >symbolic calculations. > >Any advice would be highly appreciated > >Christopher Grinde > > Don't quite understand your case, just guessing, would Plus @@ f /@ Sm do it? -- Hartmut