Re: Dependent dynamic controls

*To*: mathgroup at smc.vnet.net*Subject*: [mg100749] Re: Dependent dynamic controls*From*: István <replicatorzed at gmail.com>*Date*: Fri, 12 Jun 2009 05:47:06 -0400 (EDT)*References*: <h02vfq$863$1@smc.vnet.net> <h0l49i$oq2$1@smc.vnet.net>

Thank you all for your answers, the solution - as I now realize - is pretty simple, I should have fiddled a bit more with the code. Thanks again. Istvan On Jun 9, 12:37 pm, Albert Retey <a... at gmx-topmail.de> wrote: > Hi, > > I think you can understand what happens when using some extra prints: > > Module[{sw = True, a, b, c, n, assign}, > > assign[switch_, x_] := If[switch, > a = x; c = f@x; n = Position[aSet, x][[1, 1]], > b = x; c = g@x; n = Position[bSet, x][[1, 1]] > ]; > > assign[sw, First@If[sw, aSet, bSet]]; > Print[{a, b, c, n}]; > Panel@Column@{ > Dynamic@Column@{sw, If[sw, a, b], c, n}, > Grid[{{ > "a", > RadioButton[Dynamic[sw, (sw = #; assign[#, First@aSet]) = &], > True], > PopupMenu[Dynamic[a, assign[sw, #] &], aSet, > Enabled -> Dynamic[sw]] > }, { > "b", > RadioButton[Dynamic[sw, (sw = #; assign[#, First@bSet]) = &], > False], > PopupMenu[Dynamic[b, (Print[{sw, #}]; assign[sw, #]) &], b= Set, > Enabled -> Dynamic[! sw]] > }}] > } > > ] > > so what we learn is that actually everything works as intended, but then > in the end the initialization of the PopupMenu calls the setter function > once because b has no value yet. Whether this is what one should expect > or not I don't know, maybe you can find something in the documentation. > It is very easy to correct, though, by initializing b (in case sw is > initialized to False you might want to also initialize a): > > Module[{sw = True, a = aSet[[1]], b = bSet[[1]], c, n, assign}, > > assign[switch_, x_] := If[switch, > a = x; c = f@x; n = Position[aSet, x][[1, 1]], > b = x; c = g@x; n = Position[bSet, x][[1, 1]] > ]; > > assign[sw, First@If[sw, aSet, bSet]]; > > Panel@Column@{ > Dynamic@Column@{sw, If[sw, a, b], c, n}, > Grid[{{ > "a", > RadioButton[Dynamic[sw, (sw = #; assign[#, First@aSet]) = &], > True], > PopupMenu[Dynamic[a, assign[sw, #] &], aSet, > Enabled -> Dynamic[sw]] > }, { > "b", > RadioButton[Dynamic[sw, (sw = #; assign[#, First@bSet]) = &], > False], > PopupMenu[Dynamic[b, assign[sw, #] &], bSet, > Enabled -> Dynamic[! sw]] > }}] > } > > ] > > I have also rearranged some Dynamics since the controls need not be > recreated every time one of the variables changes. > Another suggestion would be to use DynamicModule instead of just Module, > but that depends also on what you really try to achieve. With Module you > will create a set of variables at each call, and they will persist for > the rest of the session. > > hth, > > albert