Re: Question regarding replacement
- To: mathgroup at smc.vnet.net
- Subject: [mg63862] Re: Question regarding replacement
- From: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>
- Date: Fri, 20 Jan 2006 04:32:16 -0500 (EST)
- Organization: Uni Leipzig
- References: <dqn812$la9$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi, if d/(b*c)==theta it is better to replace symbols, i.e., expr/. d -> theta*b*c and hope that Mathematica does the right cancelations. Regards Jens <michael_chang86 at hotmail.com> schrieb im Newsbeitrag news:dqn812$la9$1 at smc.vnet.net... | Hi, | | Often, when manipulating symbolic results, one might want to replace | some symbols with "simpler" expressions, and typically, I've managed | this with "/.". However, suppose that | | In[1]: a = b c/d | | and I know that d/(b c) = theta. Unfortunately, | | In[2]: params={d/(b c)->theta}; a/.params | does *not* yield 1/theta. How can I achieve this simply *without* | redefining params? | | (This (too) simple example is meant to demonstrate some difficulties | that I typically encounter when trying to replace symbols in *much* | more complicated expressions, where, sometimes, the symbols that I am | trying to replace are inverted ... :( ) | | My apologies in advance, since this seems embarassingly simple, but any | help or suggestions would be greatly appreciated! | | Regards, | | Michael |