Re: difference between two commands

*To*: mathgroup at smc.vnet.net*Subject*: [mg121647] Re: difference between two commands*From*: Heike Gramberg <heike.gramberg at gmail.com>*Date*: Sat, 24 Sep 2011 22:31:18 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201109230742.DAA07668@smc.vnet.net>

By default, the variables appearing in a Manipulate are localized. This means that for each variable in Manipulate a unique symbol is created to represent this symbol (similar to for example Module). In this case, the c in Manipulate will internally be represented by something like FE`c$$512. Try for example Manipulate[HoldForm[c], {c, 0, 1}] to see what the internal name of the variable c is. The c appearing in the definition of p is a global variable and is different to the c appearing in the Manipulate so it won't get replaced by the value of the local c when you're trying to plot p inside the Manipulate. To get the right behaviour you could do something like Clear[p]; p[c_, x_] := Sin[c x] Manipulate[Plot[p[c, x], {x, 0, 10}], {c, 1, 2}] Alternatively you could set LocalizeVariables->False, but this might cause all sorts of undesired side effects so you should be careful with that. Heike. On 23 Sep 2011, at 09:42, Luiz M. Carvalho wrote: > Hi, > > Let > p := Sin[c x] > Please, could someone explain to me the difference between those two > commands > > Manipulate[Plot[p, {x, 0, 10}], {c, 1, 2}] and Manipulate[ Plot[Sin[c > x], {x, 0, 10}], {c, 1, 2}] > > Thanks > Luiz >

**References**:**difference between two commands***From:*"Luiz M. Carvalho" <luizmc@gmail.com>