RE: PatternMatching with Dt[]
- To: mathgroup at smc.vnet.net
- Subject: [mg37301] RE: [mg37264] PatternMatching with Dt[]
- From: "DrBob" <drbob at bigfoot.com>
- Date: Tue, 22 Oct 2002 04:47:43 -0400 (EDT)
- Reply-to: <drbob at bigfoot.com>
- Sender: owner-wri-mathgroup at wolfram.com
This works: Dt[x] /. HoldPattern@Dt[arg_] -> f[arg] The problem apparently is this: In[7]:=Dt[x_] Out[7]=Dt[x]*Derivative[1, 0][Pattern][x, _] That seems odd to me, and I'm not sure why Unevaluated doesn't help. DrBob -----Original Message----- From: Johannes Ludsteck To: mathgroup at smc.vnet.net [mailto:johannes.ludsteck at wiwi.uni-regensburg.de] Subject: [mg37301] [mg37264] PatternMatching with Dt[] I would like to replace Dt[x_] in a complex expression. For example consider Dt[x]/.Dt[arg_]->f[arg] where x is a pure Symbol (has no value). However, Mathematica refuses apply the rule. Various other attempts, for example Unevaluted[Dt[arg_]]:>f[arg] and HoldForm[...] were unsuccessful. I managed to circumvent the problem by Dt[x]/.Dt->fun However, I were more happy if I understood why the first attempt was not successful. Can someone explain? Best regards, Johannes Ludsteck <><><><><><><><><><><><> Johannes Ludsteck Economics Department University of Regensburg Universitaetsstrasse 31 93053 Regensburg Phone +49/0941/943-2741