RE: How to plot...

*To*: mathgroup at smc.vnet.net*Subject*: [mg46049] RE: [mg46030] How to plot...*From*: "David Park" <djmp at earthlink.net>*Date*: Tue, 3 Feb 2004 18:20:53 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Oliver, If this is a plotting problem, then I don't completely understand your question. Because of the adaptive algorithim for picking points Mathematica never actually hits the x = 0 case. But it gets so close that you can't tell the difference. Plot[Sin[x]/x, {x, 0, Pi}, Frame -> True]; Even with a symmetrical domain Mathematica misses the x = 0 point. Plot[Sin[x]/x, {x, -Pi, Pi}, Frame -> True]; But if you calculate a set of points for making a ListPlot, then you can make certain that it gets the x = 0 point. Now you need your special definition. f[x_] := Which[x == 0, 1, True, Sin[x]/x] pts = Table[{x, f[x]}, {x, 0, Pi, Pi/24}]; ListPlot[pts, PlotJoined -> True, Frame -> True]; But this doesn't look any different than the first plot and loses the use of Mathematica's adaptive algorithm. If you want to specifically mark the x = 0 point, you could use... Plot[Sin[x]/x, {x, 0, Pi}, Frame -> True, Epilog -> {AbsolutePointSize[5], Point[{0, f[0]}]}]; David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: Oliver Kowalke [mailto:oliver.kowalke at t-online.de] To: mathgroup at smc.vnet.net Hello, I want to plot sin(x)/x on x=0. f3 := Which[x==0,1,0<x,Abs[Sin[x]/x]]; F3 ist defined on x=0 (analytische Fortsetzung). How can I force mathematica to plot the graph on x=0? thx, Oliver