Re: y-axis direction
- To: mathgroup at smc.vnet.net
- Subject: [mg116515] Re: y-axis direction
- From: Peter Breitfeld <phbrf at t-online.de>
- Date: Fri, 18 Feb 2011 04:33:36 -0500 (EST)
- References: <ijisli$27u$1@smc.vnet.net>
"Rob Y. H. Chai" wrote: > Hi all, > > In the Plot command, the convention for y-axis is up for positive values. Is > there an easy way to reverse the y-axis direction i.e. pointing down for > increasing positive y values? Thanks. > > Rob Chai You can plot -f[x] and then adjust the labels on the y-axis. Try this: Options[plotyDown] = Options[Plot]; plotyDown[f_, {x_, von_, bis_}, opts:OptionsPattern[]] := Module[{yTicks, vz, pp}, vz[{n_, l_?NumericQ, rest__}] := {n, -l, rest}; vz[{n_, rest__}] := {n, rest}; pp = Plot[-f, {x, von, bis}, opts]; yTicks = vz /@ (AbsoluteOptions[pp, Ticks][[1, 2, 2]]); Plot[-f, {x, von, bis}, Ticks -> {Automatic, yTicks}, opts] ] Example: f[x_] := x^2/Sin[x] GraphicsRow[{ Plot[f[x], {x, -\[Pi], 2 \[Pi]}, PlotRange -> {-50, 60}], plotyDown[f[x], {x, -\[Pi], 2 \[Pi]}, PlotRange -> {-50, 60}]}] -- _________________________________________________________________ Peter Breitfeld, Bad Saulgau, Germany -- http://www.pBreitfeld.de