MathGroup Archive: April 2009 [01085]

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

Differential Equation, pendulum, change of variable plot

To: mathgroup at smc.vnet.net
Subject: [mg99213] Differential Equation, pendulum, change of variable plot
From: gareth <schmit at hotmail.co.uk>
Date: Thu, 30 Apr 2009 06:21:01 -0400 (EDT)

Hello, thanks for taking the time to help sort out my query.

I am in the middle of investigating non linear pendulum. 
The equations of motion are 
w'[t]=-(1/q)w[t]-Sin[Î¸[t]] + g Cos[wD t]

Theta is the displacement, w the frequency, wD the driving frequency and g the drive amplitude.
Basically so far a I have plotted w vs theta to show chaos, however now I want to create a bifurcation diagram,
like this http://www.physics.drexel.edu/~gbyrne/Bif_g.jpg
This is done as far as I know is plotting w at the start of every drive cycle against g.
But I cant figure out how to do this,
maybe so sort of Do loop with the NDSolve of the differential equation.
Any help would be much appreciated

Prev by Date: Re: HoldForm in defined function doesn't seem to work

Next by Date: Re: why is this happening?

Previous by thread: MapAt problem with passing List

Next by thread: New Wolfram Tutorial Collection documentation is ready