Re: Question about pattern matching
- To: mathgroup at smc.vnet.net
- Subject: [mg34080] Re: [mg34057] Question about pattern matching
- From: Sseziwa Mukasa <mukasa at jeol.com>
- Date: Thu, 2 May 2002 03:49:19 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
On Wednesday, May 1, 2002, at 08:00 AM, Mike Varney wrote: > Hello. > I have a rather straight forward question on pattern matching. > > Say that I have a expression given as: > > (kg m^2) /(s^2) > > When I try a pattern matching substitution such as: > > (kg m^2) /(s^2) /. (kg m)/(s^2) -> n > > Returns: > (kg m^2) /(s^2) > > > Am I missing some sort of rule? How can I do this sort of pattern > matching. > > Thanks for you help. > Mike > > Use FullForm to find the right form: FullForm[(kg m^2)/s^2] is Times[kg, Power[m, 2], Power[s, -2]] so (kg m^2) /(s^2) /. Times[kg, Power[m, 2], Power[s, -2]] -> n works as does (kg m^2)/s^2/.kg m^2 s^-2->n Regards, Ssezi