Re: Vectorlength independet of axis-scale using VectorPlot?

*To*: mathgroup at smc.vnet.net*Subject*: [mg124465] Re: Vectorlength independet of axis-scale using VectorPlot?*From*: "Oleksandr Rasputinov" <oleksandr_rasputinov at hmamail.com>*Date*: Fri, 20 Jan 2012 01:54:51 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <jf8veo$5pb$1@smc.vnet.net>

On Thu, 19 Jan 2012 11:40:08 -0000, Robert Steinfelder <rsteinfe at techfak.uni-bielefeld.de> wrote: > Hi, > > given the following code: > > \[Gamma] := 3 > a := 0.3 > \[Epsilon] := 0.1 > > graphs := Plot[{-v*(v - a)*(v - 1), v/\[Gamma]}, {v, -0.4, 1.5}, > PlotRange -> {{-0.4, 1.3}, {-0.2, 0.3}}, > PlotStyle -> {{Black, Thick}, {Black, Thick}}, AspectRatio -> 1, > AxesStyle -> Arrowheads[0.03] ] > > vecs := VectorPlot[{-v*(v - a)*(v - 1) - > w, \[Epsilon]*(v - \[Gamma]*w)}, {v, -0.4, 1.2}, {w, -0.2, 0.3}, > Axes -> True, VectorPoints -> 15, > VectorScale -> {0.03, Scaled[1], None}] > > Show[graphs, vecs, AxesLabel -> {"v", "w"}, AspectRatio -> 1] > > The vectors of this vectorfield have all the same (absolute) length, of > course. But > due to the axis-scale, vectors in vertical orientatian are plottet > longer than > the others. Is it possible to correct that, so that all the > vectors have the same (relative) length? > > Regards, > Rob > The way that seems to make most sense to me is to set AspectRatio -> Automatic. Of course, this means you end up with a plot having an unusual aspect ratio, but if you want the vectors to be of the same relative size yet still quantitatively meaningful I'm not sure that there's a better way to accomplish this.