Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2002
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2002

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Getting Coordinates from plot

  • To: mathgroup at smc.vnet.net
  • Subject: [mg32967] Re: [mg32953] Getting Coordinates from plot
  • From: BobHanlon at aol.com
  • Date: Fri, 22 Feb 2002 01:48:50 -0500 (EST)
  • Sender: owner-wri-mathgroup at wolfram.com

In a message dated 2/21/02 4:04:10 AM, uceswga at ucl.ac.uk writes:

>I would like a list of coordinates so that I can analyze them further
>and possibly import into a "prettier" graphing package. What should
>I do when using the NDSolve function?
>
>I have tried the menu command: Input -> Get Graphics Coordinates.
>This requires me to use Mod1 key which I don't have on my keyboard.
>
>How can I get coordinates of the plot from the following:
>
>
>Pends[init1_, init2_, time_, k_, {c_, w_, p_}] := 
>      Module[{}, 
>        pend = NDSolve[{
>     x1''[t] + c x1'[t] + ((1 + p Cos[w t])) Sin[x1[t]] == k (x2[t] - x1[t]),
>
>          x2''[t] + c x2'[t] + ((1 + p Cos[w t])) Sin[x2[t]] == k (x1[t]
>- x2[t]), 
>              x1[0] == init1[[1]], x1'[0] == init1[[2]], 
>              x2[0] == init2[[1]], x2'[0] == init2[[2]]}, 
>         {x1, x2}, {t, 0, time}, 
>         MaxSteps -> 200000]; 
>         xd[t_] := x1[t] /. pend[[1]]; 
>         xdd[t_] :=x1'[t] /.pend[[1]]; 
>         xr[t_] := x2[t] /. pend[[1]]; 
>         xrd[t_] :=x2'[t] /.pend[[1]];
>         ];
>   c = 0.1;  w = 2.0;  p = 2.0;
>   Pends[{1.37, 0}, {-1.17, 0}, 5000, 0.0, {c, w, p}];
>   ParametricPlot[{ {xd[t], xdd[t]}, {xr[t], xrd[t]}}, {t, 1000, 1500}];
>

plt = ParametricPlot[{ {xd[t], xdd[t]}, {xr[t], xrd[t]}}, {t, 1000, 1500}];

The data for the first plot is plt[[1, 1, 1, 1, 1]]

The second plot is plt[[1, 2, 1, 1, 1]]

To compare with the original plot

Needs["Graphics`Graphics`"];
DisplayTogether[
    ListPlot[plt[[1, 1, 1, 1, 1]], PlotJoined -> True],
    ListPlot[plt[[1, 2, 1, 1, 1]], PlotJoined -> True]];


Bob Hanlon
Chantilly, VA  USA


  • Prev by Date: Re: Getting Coordinates from plot
  • Next by Date: Re: Notebook manipulation
  • Previous by thread: Re: Getting Coordinates from plot
  • Next by thread: Re: Getting Coordinates from plot