Re: trying to "simplify" very large output
- To: mathgroup at smc.vnet.net
- Subject: [mg83092] Re: trying to "simplify" very large output
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Sat, 10 Nov 2007 03:43:48 -0500 (EST)
- Organization: The Open University, Milton Keynes, UK
- References: <fh1btf$an7$1@smc.vnet.net>
Basjsmit wrote: > When I used Mathematica to solve a certain expression, the output was > extremely large, somewhere around 10 000 characters. When I looked more > closely at the output, I noticed certain frases kept repeating. I havent > found anything in the help, but Im wondering if there is a function that can > replace those frases with a variable and set that variable once. An example: > > t-> -(y z-v x Cos[k]^2-v x Sin[k]^2)/(z^2-x^2 Cos[k]^2-x^2 Sin[k]^2)-1/2 > \[Sqrt]((4 (y z-v x Cos[k]^2-v x Sin[k]^2) ........ > > becomes: > > A = y z-v x Cos[k]^2-v x Sin[k]^2 > B = z^2-x^2 Cos[k]^2-x^2 Sin[k]^2 > t-> -A / B -1/2 \[Sqrt]((4 A ........ > > Thanks in advance, Bas > > PS: just curious, is there a name for the proces I described above? Transformation rules and replacement operators are your friends here. You should familiarize yourself with the following set of tutorials, available in the documentation center tutorial/TransformationRulesAndDefinitionsOverview or online at http://reference.wolfram.com/mathematica/tutorial/TransformationRulesAndDefinitionsOverview.html Regards, -- Jean-Marc