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

Re: ODEs and phase portraits

• To: mathgroup at smc.vnet.net
• Subject: [mg14773] Re: ODEs and phase portraits
• From: Dr Phillip Kent <p.kent at ic.ac.uk>
• Date: Sat, 14 Nov 1998 03:08:04 -0500
• Organization: Imperial College
• References: <728kp1$ehc@smc.vnet.net> <72fad6$feq$2@dragonfly.wolfram.com>
• Sender: owner-wri-mathgroup at wolfram.com

Kevin J. McCann wrote:
> 
> Try this one:
> 
>  ...............................
>
> phantomlord at my-dejanews.com wrote in message <728kp1$ehc at smc.vnet.net>...
> >I am trying to write a function such that I have the following ODE:
> >x''(t)+epsilon*(x(t)^2-1)*x'(t)+x(t)==0  [1] where epsilon is to be one
> >of the parameters in the function. I want to beable to draw out the
> >phase portraits for the equation for different values of epsilon.
> >
> ..............................
> >Perhaps there is a built in function that will allow me to do this? If
> >not do, can anybody suggest another way to do this?
> >
> >Also after plotting the trajectory is there any way to determine the
> >direction of it in Mathematica?
> >
> >thanks for you time.
> >Paul
> >

I have prepared a little code package to make trajectories and  phase
portraits easier to handle - please take a look:


http://metric.ma.ic.ac.uk/dynamics


----------------------------------+----------------------------
 Dr Phillip Kent                  | tel: +44 (0)171 594 8503  
 The METRIC Project               | fax: +44 (0)171 594 8517
 Mathematics Department           | 
 Imperial College                 | p.kent at ic.ac.uk 
 London SW7 2BZ, U.K.             | http://metric.ma.ic.ac.uk/
----------------------------------+----------------------------
      "In designing tools we are designing ways of being"