Re: Adding Colorfunction causing poor plot quality

*To*: mathgroup at smc.vnet.net*Subject*: [mg101288] Re: Adding Colorfunction causing poor plot quality*From*: "Sjoerd C. de Vries" <sjoerd.c.devries at gmail.com>*Date*: Tue, 30 Jun 2009 06:32:57 -0400 (EDT)*References*: <h29cc0$bct$1@smc.vnet.net>

John Fultz already explained it in this thread: http://groups.google.com/group/comp.soft-sys.math.mathematica/ browse_frm/thread/a956d8eee41f8923# (http://tinyurl.com/l44dmm) Cheers -- Sjoerd On Jun 29, 5:28 am, Porscha Louise McRobbie <pmcro... at umich.edu> wrote: > Hi, > > I want to understand why adding a ColorFunction seems to worsen the > resolution of my graphics. I have two side-by-side animations, one of > which is a complex function Psi, where the shape is the square modulus > and the ColorFunction is Arg[Psi]. > > I have the following: > > Clear[Psi, X, anima, dx0, dk, k0] > DynamicModule[{dk, k0, Psi, anima}, dk = .5; dx0 = 0.5/dk; > > Psi[x_, k0_, t_] := > 1/((4 Pi^2 dk^2)^(1/4)) ( > 2 E^((k0^2 t - 2 k0 x - 2 I dk^2 x^2)/(2 I - 4 dk^2 t)) > Sqrt[Pi])/Sqrt[1/dk^2 + 2 I t]; > > anima[x_, k0_] := > Animate[ > > GraphicsRow[{Plot[Abs[Psi[x, k0, t]]^2, {x, -20, 20}, > PlotRange -> {{-20, 20}, {0, 1.1}}, Filling -> Axis, > ColorFunction -> (Hue[(Arg[Psi[#1, k0, t]])/(2 Pi)] &), > ColorFunctionScaling -> False, PerformanceGoal -> "Quality= ", > PlotPoints -> 10, MaxRecursion -> 3], > > Show[ > Plot[Sqrt[1 + T^2/(4 dx0^4)], {T, 0, t}, > PlotStyle -> {Thick, Blue}, PlotRange -> {{0, 15}, {0, 7.= 5}}], > Plot[dk T/dx0, {T, 0, 15}, > PlotStyle -> {Black, Dashed, Thick}]]}, ImageSize -> 600]= , > > {t, 0.0001, 15}, AnimationRunning -> False]; > > Manipulate[anima[x, k0], > Style["Wavepacket Center", Bold, > 16], {{k0, 0, > Style["\!\(\*SubscriptBox[\"k\", \"0\"]\)", 14]}, -1.25, 1.25, > Appearance -> "Labeled", ImageSize -> Small}, > ControlPlacement -> Left, SaveDefinitions -> True]] > > The resolution on both plots isn't great. I've tried adjusting both > PlotPoints and MaxRecursion, but it doesn't seem to improve the > quality at all, it only makes the animation controls (Play/Pause) more > slow to respond when clicked. I see the same problems if I change the > ColorFunction to something simpler like "Rainbow". > > However, if I remove the options ColorFunction and > ColorFunctionScaling, the plots are not jagged, the resolution is > great, and the animation smoother. > > 1. Is there another way to add a ColorFunction to such a filled plot? > 2. Why should adding a colorfunction to the first element of my > GraphicsRow (which worsens the resolution), also worsen the resolution > of the second element of my GraphicsRow? > > Thanks in advance, > Porscha