Re: Graphing sets of linear inequalities

*To*: mathgroup at smc.vnet.net*Subject*: [mg53969] Re: [mg53910] Graphing sets of linear inequalities*From*: "David Park" <djmp at earthlink.net>*Date*: Sat, 5 Feb 2005 03:16:35 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Here are two methods for making your plot. << Graphics`FilledPlot` << Graphics`Colors` << Graphics`InequalityGraphics` The first method used FilledPlot. We need to change your inequalities into one for y values. -2 < x + 2y < 4; (# - x)/2 & /@ % (1/2)*(-2 - x) < y < (4 - x)/2 FilledPlot[{(1/2)*(-2 - x), (4 - x)/2}, {x, -2, 4}, Fills -> LightCoral, AspectRatio -> Automatic, Frame -> True, FrameLabel -> {x, y}, Axes -> None, PlotLabel -> -2 < x + 2*y < 4, Background -> Linen, ImageSize -> {450, Automatic}]; The second method is to use InequalityPlot. InequalityPlot[ -2 < x + 2y < 4, {x, -2, 4}, {y, -3, 3}, Fills -> LightCoral, Frame -> True, FrameLabel -> {x, y}, Axes -> None, PlotLabel -> -2 < x + 2y < 4, Background -> Linen, ImageSize -> {450, Automatic}]; Note that a liberal use of plot options are often necessary to make a nice looking plot. David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: DJ Craig [mailto:spit at djtricities.com] To: mathgroup at smc.vnet.net How do you graph something like this: -2 = x + 2y = 4 I need the areas where this is true to be shaded, and solid lines at x + 2y = -2 and x + 2y = 4.