Re: Simple Concept I can't figure out! Making rules?
- To: mathgroup at smc.vnet.net
- Subject: [mg38076] Re: Simple Concept I can't figure out! Making rules?
- From: "Kevin J. McCann" <kjm@KevinMcCann>
- Date: Tue, 3 Dec 2002 04:28:43 -0500 (EST)
- References: <as5pgp$n96$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
ans = Solve[2x-1==0,x][[1]]//N answer = x/.ans Note that the [[1]] construct effectively turns ans into {x->0.5}, without it the above answer would be {0.5} not 0.5. Kevin "Stan" <snarten at runbox.com> wrote in message news:as5pgp$n96$1 at smc.vnet.net... > Even though it's frowned upon by the engineering college, i use > mathematica a lot of the stuff that would take pages of code in > another system. I have most basic functions and operations down, but I am > lacking one basic thing I need to do to be able to program more > problems successfully: > > here is my problem: > > Lets say you solve an equation using "Solve" > > Solve[2x - 1 == 0, x] // N > > {{x -> 0.5}} > > How would I then use the result of "Solve" (0.5) and assign it to a > new variable, like "answer" for further calculations? > > I think it has something to do with /. and -> rules of some sort, but > I can't get this simple concept to work! > > Thanks for the help. > > -Stan >