Cool example with ContourPlot+EvaluationMonitor

*To*: mathgroup at smc.vnet.net*Subject*: [mg125518] Cool example with ContourPlot+EvaluationMonitor*From*: psycho_dad <s.nesseris at gmail.com>*Date*: Sat, 17 Mar 2012 02:49:44 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

The following example shows in real-time (sort of) how ContourPlot calculates a contour (in this example a unit circle): f[x_, y_, freeze_] := (Pause[freeze]; (x^2 + y^2)) data = {}; freeze = 0.04; Dynamic[ListPlot[data, Frame -> True, AspectRatio -> 1, PlotStyle -> Blue, PlotRange -> {{-1.6, 1.6}, {-1.6, 1.6}}, Epilog -> Circle[{0, 0}]]] ContourPlot[f[x, y, freeze] == 1, {x, -1.5, 1.5}, {y, -1.5, 1.5}, EvaluationMonitor :> AppendTo[data, {x, y}]]; Initially I just wanted to get all the points from ContourPlot, but then it dawned on me that using Dynamic I could do that in real time! I hope you like it :D Cheers PS Change the parameter freeze (set to 0.04 secs) to make the animation slower or faster. PPS This is so cool, I just knew I had to share it!