MathGroup Archive 2009

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

Search the Archive

Re: Question about how to graph the vector field for the

  • To: mathgroup at smc.vnet.net
  • Subject: [mg97950] Re: Question about how to graph the vector field for the
  • From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
  • Date: Thu, 26 Mar 2009 05:23:08 -0500 (EST)
  • References: <gqacvk$jfv$1@smc.vnet.net>

Hi,

StreamPlot[{x, 2 x - y}, {x, -3, 3}, {y, -3, 3}]

?

Regards
   Jens

Bob Hanlon wrote:
> Clear[y]
> 
> y[c_][x_] =
>   y[x] /.
>     DSolve[y'[x] == 2 x - y[x], y[x], x][[1]] /.
>    C[1] :> c
> 
> c E^-x+2 (x-1)
> 
> D[y[c][x], x] == 2 x - y[c][x] // Simplify
> 
> True
> 
> Plot[
>   Evaluate[
>    Table[
>     Tooltip[y[c][x]],
>     {c, -3, 5}]],
>   {x, -1/2, 3}]
> 
> Plot3D[y[c][x], {x, -1/2, 3}, {c, -3, 5}]
> 
> Manipulate[
>   Plot[y[c][x], {x, -1/2, 3},
>    PlotRange -> {-8, 5}],
>   {c, -3, 5}]
> 
> 
> 
> Bob Hanlon
> 
> 
> On Mon, Mar 23, 2009 at 7:35 AM , jo1e984 at gmail.com wrote:
> 
>> i need to graph the vector field and the family of solutions for the
>> DE: dy/dx=2x-y
>> and i tried the graph the vector field, but while i tried to use the
>> VectorFieldPlot it show up some kind of wierd graph...
>> and i cannot even get start on the "family of Solutions"
>> graph...searched online but still cannot figure out.
>> hope some pros can help me out on this...thx alot~!!
>> Bluefly
> 


  • Prev by Date: Re: help^please
  • Next by Date: HoldAll for Integrate
  • Previous by thread: Re: Question about how to graph the vector field for the
  • Next by thread: Histograms and Iterators - Beginner Question