Re: Re: Equivalent functionality to colorbar in Mathematica?

*To*: mathgroup at smc.vnet.net*Subject*: [mg81829] Re: [mg81804] Re: Equivalent functionality to colorbar in Mathematica?*From*: DrMajorBob <drmajorbob at bigfoot.com>*Date*: Thu, 4 Oct 2007 04:28:24 -0400 (EDT)*References*: <200709300744.DAA20164@smc.vnet.net> <fdt3a6$roe$1@smc.vnet.net> <6810751.1191429101231.JavaMail.root@m35>*Reply-to*: drmajorbob at bigfoot.com

OK, I've satisfied myself that DensityPlot doesn't retain, within it, any direct mention of the maximum or minimum function value. There are no Real numbers near the maximum, for instance, even in the Normal version of the plot. Possibly the truth is intricately coded somewhere, but I'm beginning to doubt it. Bobby On Wed, 03 Oct 2007 05:33:46 -0500, Will Robertson <wspr81 at gmail.com> wrote: > Hi, > > That's a nice way to do it, David. Much better than what I was looking > at :) > For my own conveniece I've wrapped my attempt (but with a 2D density > plot instead) into a function (appended below). > > My main concern with the thing is extracting the min/max values of the > colorbar: my method currently uses Sow[] on the expression inside > DensityPlot with an EvaluationMonitor. This seems very wasteful (since > the expression is being evaluated twice for each data point, right?) > -- is there a better way? > > Many thanks, > Will > > Options[ColorbarPlot] = {Colors -> "PigeonTones", CLabel -> "", > XLabel -> "", YLabel -> "", Title -> "", NContours -> 15, > Height -> 8*72/2.54}; > ColorbarPlot[expr_, xr_, yr_, OptionsPattern[]] := > Module[{contours}, > rawPlot = > DensityPlot[expr, xr, yr, > EvaluationMonitor :> Sow[expr], > ImageSize -> {Automatic, OptionValue[Height]}, > ColorFunction -> OptionValue[Colors], > FrameLabel -> {{OptionValue[YLabel], None}, {OptionValue[XLabel], > OptionValue[Title]}}] // Reap; > contours = rawPlot[[2, 1]]; > Row[{rawPlot[[1]], > ContourPlot[ > y, {x, 0, (Max[contours] - Min[contours])/ > OptionValue[NContours]}, > {y, Min[contours], Max[contours]}, > Contours -> OptionValue[NContours], > ImageSize -> {Automatic, OptionValue[Height]}, > ColorFunction -> OptionValue[Colors], > AspectRatio -> Automatic, PlotRange -> Full, > PlotRangePadding -> 0, > FrameLabel -> {{"", ""}, {"", OptionValue[CLabel]}}, > FrameTicks -> {{All, None}, {{{0, ""}}, None}}]}] > ] > ColorbarPlot[x^2 + y^2, {x, -10, 10}, {y, -10, 10}, XLabel -> "x", > YLabel -> "y", Title -> "Title", CLabel -> "Range"] > > > -- DrMajorBob at bigfoot.com