Re: Help getting values from NDSolve
- To: mathgroup at smc.vnet.net
- Subject: [mg6826] Re: [mg6783] Help getting values from NDSolve
- From: penny at suu.edu (Des Penny)
- Date: Mon, 21 Apr 1997 02:03:24 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
>I'm relatively new to Mathematica and need some help with the NDSolve
>function. I have used it to solve an ordinary differential equation and got
>the expected interpolating function which I then plotted. The plot is great
>but I would like a list of coordinates so that I can analyze them further
>and possibly import into a "prettier" graphing package.
>
>Any help would be appreciated.
>
>Please email and post (mosser at earthlink.net)
Hi Chris:
I decided to do some more work on this question. I was interested in
pulling the data directly from the InterpolatingFunction.
Here is my code. I've given it in expanded form so that the components
would be easy to understand:
sol=NDSolve[{y'[x]==y[x],y[0]==1},y,{x,0,2}];
fun= y /. sol;
args=fun /. InterpolatingFunction->List;
xvalues=args[[1,3,1]];
yvalues=Map[First,args[[1,4]]];
data=Transpose[{xvalues,yvalues}];
ListPlot[data]
Hope this helps.
Cheers,
Des Penny
-------------------------------
Des Penny
Physical Science Dept.
Southern Utah University
Cedar City, UT 84720
VOICE: (Office): (801) 586-7708
(Home) : (801) 586-2286
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e-mail: penny at suu.edu
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