Re: Dynamically changing 2 interdependent variables.

*To*: mathgroup at smc.vnet.net*Subject*: [mg81456] Re: Dynamically changing 2 interdependent variables.*From*: Norbert Marxer <marxer at mec.li>*Date*: Sun, 23 Sep 2007 21:20:43 -0400 (EDT)*References*: <fd57vj$25b$1@smc.vnet.net>

On 23 Sep., 10:26, Michael Knap <michael.j.k... at comcast.net> wrote: > Ok, I have looked over the Documentation, but I still haven't quite > figured out how to do exactly what I want to do. > > I am working on a Physics app dealing with waves, so I want to be able > to input a wave number either expressly, as k, or in terms of lambda. > > This is the relationship: k = (2 Pi) / lambda . > > I want to be able to change either variable in a Manipulate[] function, > and have the other update appropriately. > > This is what I have started with: > > Manipulate[ > Dynamic[ > Row[{ > TraditionalForm[k = (2 Pi)/lam], > " = ", > TraditionalForm[2 Pi]/TraditionalForm[lam = (2 Pi)/k] > }] > ], > {{k, 1}, .00001, 1}, > {{lam, 2 Pi}, 2 Pi, 100} > ] > > Notice how changing the lam slider works as expected. Changing the k > slider does not. > > Any help is appreciated. Hello It should work if you wrap Dynamic just aroung one side of your equation: e.g. Manipulate[ Row[{Dynamic@TraditionalForm[k = (2 Pi)/lam], " = ", TraditionalForm[2 Pi]/TraditionalForm[lam = (2 Pi)/k]}], {{k,1}, . 00001, 1}, {{lam, 2 Pi}, 2 Pi, 100}] Best Regards Norbert Marxer