Re: "Alternating" function
- To: mathgroup at smc.vnet.net
- Subject: [mg63275] Re: [mg63260] "Alternating" function
- From: "David Park" <djmp at earthlink.net>
- Date: Thu, 22 Dec 2005 00:04:36 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Renan, What about using Fold? Fold[x + #2*f[#1] & , x, Table[(-1)^i, {i, 5}]] x - f[x + f[x - f[x + f[x - f[x]]]]] David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: Renan [mailto:renan.birck at gmail.com] To: mathgroup at smc.vnet.net Hello, I want to make a "nested function" like: x + f[x - f[x + f[x - f[x + f[x]]]]]. I've tried using Nest but I don't find how to keep switching between Plus and Minus: I would need something that would return an "index" so I could keep track of when I need to "switch" the operation. (e.g. if the "index" is odd, the operation is "Plus", otherwise is "Minus") How can I make this? I looked in the help but didn't find any informations. Thanks.