Re: Drawing a Line From One Plot to Another

*To*: mathgroup at smc.vnet.net*Subject*: [mg127702] Re: Drawing a Line From One Plot to Another*From*: Bob Hanlon <hanlonr357 at gmail.com>*Date*: Wed, 15 Aug 2012 03:38:06 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net*References*: <20120814082121.B6E906849@smc.vnet.net>

It might be easier to use a single plot with one function offset. That would keep you in a single set of coordinates. y1[x_] = x^2; y2[x_] = 2 x; pts = {x, y1[x]} /. Solve[y1[x] == y2[x], x]; offset = 10; plt = Plot[ Evaluate[ {Tooltip[y1[x]] , Tooltip[y2[x] - offset, y2[x]]}], {x, -1, 3}, Frame -> True, Axes -> False, Epilog -> { Text[#, #, {1, -2}] & /@ pts, Text[# + {0, offset}, #, {-1, 2}] & /@ ((# - {0, offset}) & /@ pts), {Thick, Line[{{-1.5, -2}, {3.5, -2}}]}, Red, AbsolutePointSize[4], Point[pts], Point[(# - {0, offset}) & /@ pts], Darker[Green], AbsoluteDashing[{10, 5}], Arrow[{#, # - {0, offset}}] & /@ pts}]; Show[plt, FrameTicks -> { Automatic, (FrameTicks /. AbsoluteOptions[plt, FrameTicks])[[2]] /. {y_, yl_?(NumericQ[#] && # < -1 &), r___} -> {y, yl + offset, r}}] However, it may be easier still to plot the multiple functions on the same plot. If necessary use two separate y axes (right and left frame axes). Plot[ Evaluate[ Tooltip /@ {y1[x] , y2[x]}], {x, -1, 3}, Frame -> True, Axes -> False, Epilog -> { Text[#, #, {-1, 2}] & /@ pts, Red, AbsolutePointSize[4], Point[pts]}] Bob Hanlon On Tue, Aug 14, 2012 at 4:21 AM, Gregory Lypny <gregory.lypny at videotron.ca> wrote: > Hello everyone, > > Say I have two plots, y=x^2 and y=2x, aligned vertically using GraphicsColumn. Their domains are aligned because x runs from -3 to +3 in both. I'd like to be able to draw a line from a point in the top graph to a point in the bottom graph. How can I do that? > > Regards, > > Gregory >

**References**:**Drawing a Line From One Plot to Another***From:*Gregory Lypny <gregory.lypny@videotron.ca>