Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2009

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

Search the Archive

Re: problems with DSolve

  • To: mathgroup at smc.vnet.net
  • Subject: [mg99428] Re: problems with DSolve
  • From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
  • Date: Tue, 5 May 2009 06:01:52 -0400 (EDT)
  • Organization: Uni Leipzig
  • References: <gtnk4s$3md$1@smc.vnet.net>
  • Reply-to: kuska at informatik.uni-leipzig.de

Hi,

may be that

Plot[Evaluate[
(x[t] /. DSolve[{x'[t] == y[t], y'[t] == -x[t], x[0] == 1, y[0]== 2}], 
{x, y}, t]), {t, 0, 5}]

will work too.

Plot[] hat the attribute HoldAll.

Regards
   Jens

szymon.stoma at gmail.com wrote:
> hello,
> 
> i am new to mathematica, therefore sorry if my question is trivial. I
> would like to understand why the following line does not work:
> 
> Plot[(x[t] /. DSolve[{x'[t] == y[t], y'[t] == -x[t], x[0] == 1, y[0]
> == 2}, {x, y}, t]), {t, 0, 5}]
> 
> whereas after splitting into two lines it works:
> sol = DSolve[{x'[t] == y[t], y'[t] == -x[t], x[0] == 1, y[0] == 2},
> {x, y}, t]
> Plot[(x[t] /. sol), {t, 0, 5}]
> 
> i would like to use Manipulate to play with boundary conditions, so
> the first notation would be highly useful.
> 
> thanks a lot for any feedback.
> 


  • Prev by Date: Re: INCLUDE A LEGEND IN A GRAPHIC
  • Next by Date: Re: why does DownValues not return all downvalues for a symbol?
  • Previous by thread: Re: problems with DSolve
  • Next by thread: Re: problems with DSolve