Re: Conditonal sum
- To: mathgroup at smc.vnet.net
- Subject: [mg50269] Re: [mg50263] Conditonal sum
- From: "David Park" <djmp at earthlink.net>
- Date: Tue, 24 Aug 2004 06:22:03 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Christopher,
Is this what you mean?
Sm = {1, 3, 4, 7, 11};
a + Plus @@ Sm
26 + a
or
Fold[Plus, a, Sm]
26 + a
David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/
From: Christopher Grinde [mailto:christopher.grinde at hive.no]
To: mathgroup at smc.vnet.net
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