Re: Coolest Mathematica trick you'll see this month

*To*: mathgroup at smc.vnet.net*Subject*: [mg96792] Re: [mg96769] Coolest Mathematica trick you'll see this month*From*: DrMajorBob <btreat1 at austin.rr.com>*Date*: Wed, 25 Feb 2009 04:02:28 -0500 (EST)*References*: <200902241047.FAA23647@smc.vnet.net>*Reply-to*: drmajorbob at bigfoot.com

I'd write it this way: Clear[doubleBallMap, c2r4, spinKet] doubleBallMap[v : {w_, x_, y_, z_}] := {y, z, Sign[x]*(w + 1)/2}/ Sqrt[v.v]; c2r4[{w_, x_}] := {Re[w], Im[w], Re[x], Im[x]}; spinKet[\[Beta]_, t_] := {Sin[\[Beta]/2] Exp[-I 2 \[Pi] t], Cos[\[Beta]/2] Exp[I 2 \[Pi] t]}; ParametricPlot3D[ Map[(doubleBallMap[c2r4[spinKet[#, t]]]) &, Range[0, \[Pi], \[Pi]/16]], {t, 0, 2 \[Pi]}] (All those Extract-ions are obtuse and distracting.) Drawing the 3D graphic initially is slow, but I don't get any problems when rotating the image. (That's what the post complained about.) I doubt most of us have "accelerometer" drivers, so I can't help you with that, either. Bobby On Tue, 24 Feb 2009 04:47:00 -0600, Chris Pemberton <cjpembo at gmail.com> wrote: > I use Linux on my machines and enjoy helping other Archlinux users in > the online forums. A fellow Arch user was having issues with > Mathematica 7. He was plotting a 3D parametric equation and > experiencing a sustained high processor load on this laptop; only > killing the kernel would allow the CPU to idle down. He found that the > laptop's accelerometer kernel driver was eating nearly 30% of the CPU > time.... You'll just have to read the forum to see the rest! > > http://bbs.archlinux.org/viewtopic.php?id=65916 > > Can any Windows or Mac users duplicate this? Or is this a Linux-only > "feature"? Or maybe this is well-known and I'm just late in finding out? > > cjpembo > -- DrMajorBob at longhorns.com

**References**:**Coolest Mathematica trick you'll see this month guaranteed***From:*Chris Pemberton <cjpembo@gmail.com>