Re: What is wrong with 2Pi?

*To*: mathgroup at smc.vnet.net*Subject*: [mg131165] Re: What is wrong with 2Pi?*From*: Bob Hanlon <hanlonr357 at gmail.com>*Date*: Sat, 15 Jun 2013 04:21:48 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-outx@smc.vnet.net*Delivered-to*: mathgroup-newsendx@smc.vnet.net*References*: <20130614085855.6E6BC6A61@smc.vnet.net>

I would guess that the problem is related to Manipulate's attribute HoldAll and that numeric constants like Pi are symbols; however, N can be used rather than specifying 6.28 {Attributes[Manipulate], Head[Pi]} {{HoldAll, Protected, ReadProtected}, Symbol} Manipulate[ Plot[Sin[a x], {x, 0, 4 Pi}, PlotRange -> {-1.05, 1.05}, AxesLabel -> {Style["x", 16, Italic], None}], {{a, 1, Style["a", 16, Italic, FontFamily -> "Times"]}, 0, 2 Pi // N, VerticalGauge[##, ImageSize -> 60] &}, ControlPlacement -> Left, FrameLabel -> Style["sin(a x)", 18, Italic, FontFamily -> "Times"]] Bob Hanlon On Fri, Jun 14, 2013 at 4:58 AM, Alexei Boulbitch <Alexei.Boulbitch at iee.lu>wrote: > Dear community, > > This works: > > Manipulate[ > Plot[Sin[a x], {x, 0, 4 Pi}], {{a, 1}, 0, 6.28, > VerticalGauge[##, ImageSize -> 50] &}, ControlPlacement -> Left] > > This > > Manipulate[ > Plot[Sin[a x], {x, 0, 4 Pi}], {{a, 1}, 0, 2 \[Pi], > VerticalGauge[##, ImageSize -> 50] &}, ControlPlacement -> Left] > > however, does not work. I cannot move the gauge in this latter case, while > it is easy to move it in the former one. > > So, if I am right, is it Pi placed instead of 6.28 that disturbs the > functioning? Please check it. Looks like a bug. > > Alexei > > > Alexei BOULBITCH, Dr., habil. > IEE S.A. > ZAE Weiergewan, > 11, rue Edmond Reuter, > L-5326 Contern, LUXEMBOURG > > Office phone : +352-2454-2566 > Office fax: +352-2454-3566 > mobile phone: +49 151 52 40 66 44 > > e-mail: alexei.boulbitch at iee.lu > > > > >

**References**:**What is wrong with 2Pi?***From:*Alexei Boulbitch <Alexei.Boulbitch@iee.lu>