Re: Simple question

*To*: mathgroup at smc.vnet.net*Subject*: [mg48087] Re: Simple question*From*: Paul Abbott <paul at physics.uwa.edu.au>*Date*: Tue, 11 May 2004 05:20:12 -0400 (EDT)*Organization*: The University of Western Australia*References*: <c7fi8a$oda$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

In article <c7fi8a$oda$1 at smc.vnet.net>, George Kamin <gwkamin at adelphia.net> wrote: > This is simple question, but I do not know how to go about searching for it > in this user groups data base. I also could not find a reference to the > solution in the "Mathematica Book". How does one assign the result of > Solve[.] or FindRoot[.] in the form {x1-> 3.14,x2->0.763} to the two > variables y1,y2 respectively?? Others have answered your question -- but I should ask you _why_ you want to assign the values (returned as rules) to variables? The idea of returning results as a list of replacement rules is to avoid explicit variable assignments. If you have vals = {x1-> 3.14,x2->0.763}; then you can substitute these values into any expression involving x1 and/or x2. For example x1^2 - x2 /. vals or ContourPlot[Evaluate[(x-x1)^2+(y-x2)^2 /. vals], {x,-5,5}, {y,-1,1}]; Sometimes variable assignment is desirable or required but, usually, the above approach is preferable. Cheers, Paul -- Paul Abbott Phone: +61 8 9380 2734 School of Physics, M013 Fax: +61 8 9380 1014 The University of Western Australia (CRICOS Provider No 00126G) 35 Stirling Highway Crawley WA 6009 mailto:paul at physics.uwa.edu.au AUSTRALIA http://physics.uwa.edu.au/~paul