RE: Apply and Heads option
- To: mathgroup at smc.vnet.net
- Subject: [mg35223] RE: [mg35213] Apply and Heads option
- From: "DrBob" <majort at cox-internet.com>
- Date: Wed, 3 Jul 2002 05:13:21 -0400 (EDT)
- Reply-to: <drbob at bigfoot.com>
- Sender: owner-wri-mathgroup at wolfram.com
You've probably seen this page: http://documents.wolfram.com/v4/RefGuide/Heads_ex.html It appears to me that Heads affects pattern matching only -- it specifies whether matching the head of a sub-expression counts as a match. If the pattern is f, does it match twice in f[f] (Heads->True) or just once (Heads->False)? It doesn't seem that Apply is sensitive to that issue. It applies a function to all expressions of a certain level (or range of levels) -- not just those that match a pattern. Bobby -----Original Message----- From: Ersek, Ted R [mailto:ErsekTR at navair.navy.mil] To: mathgroup at smc.vnet.net Subject: [mg35223] [mg35213] Apply and Heads option Hello mathgroup, --------- Apply has the Heads option. Can somebody give an example where Apply[f, expr, Heads->True] gives a different result than Apply[f, expr, Heads->False]. OR where Apply[f, expr, levelspec, Heads->True] gives a different result than Apply[f, expr, levelspec, Heads->False]. ---------- Thanks, Ted Ersek