Re: ReplaceRepeated info
- To: mathgroup at smc.vnet.net
- Subject: [mg77697] Re: ReplaceRepeated info
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Fri, 15 Jun 2007 04:31:14 -0400 (EDT)
- References: <f4r573$ber$1@smc.vnet.net>
Hi, and cnt = 0; Log[d p q r] Log[a b c d] //. Log[x_ y_] :> (cnt++; Log[x] + Log[y]) will count in cnt the number of substitutions and asking for the value of cnt will give you 6 Regards Jens alexxx.magni at gmail.com wrote: > Hi everybody, > I need to use in my program ReplaceRepeated, and also to know, after > it has been applied, how many times a replacement happened. Say, after > this: > > Log[d p q r] Log[a b c d]//.Log[x_ y_] ->Log[x] + Log[y] > > (Log[a] + Log[b] + Log[c] + Log[d]) (Log[d] + Log[p] + Log[q] + > Log[r]) > > > ... I'd need to know that it performed 6 substitutions. > There is a way with //. , or have I to resort to some loop around /. , > checking myself when no change happens anymore? > > > Thank you! > > Alessandro Magni > >