Re: Extracting data points from Plot[]

*To*: mathgroup at christensen.cybernetics.net*Subject*: [mg822] Re: [mg773] Extracting data points from Plot[]*From*: tiggj at iswaps.lonnds.ml.com (Jason Tigg SWAP GROUP ANALYST X2312 LDN)*Date*: Mon, 24 Apr 1995 02:46:09 -0400

J. Gruyer wrote > The Plot[] function does some intelligent picking of points, such that it > usually does a pretty good job of following twists and turns in a function > without plotting an excessive number of points. I'm not ecstatic about > using Mma for final output, though, so I like to export these curves to a > graphing program. > > So far, I haven't been able to figure out any way to get at this > point-picking algorithm without using Plot[]. What I'm then left with is > doing: Here's a trick which I picked up at a Mathematica conference. In[1] := data = {}; f[x_] := x^2; Plot[ AppendTo[data, {x,f[x]}]; f[x], {x,0,2}, DisplayFunction -> Identity]; data // Short Out[4] = {{0,0},{0.0833333, 0.00694444}, <<37>>, {2,4}} This method can be used to investigate where FindMinimum samples a function in its search for a minimum. Jason Tigg