Mr. Robert Long

## 1409 Reputation

14 years, 293 days
Leeds, United Kingdom

## MaplePrimes Activity

Greetings all I'm currently using an AMD Athlon system, 2GHz with 4GB Ram with 64 bit windows 7 I'm considering an intel Core i7-720QM (1.6GHz, 4 Cores/8 Threads, turbo up to 2.8 GHz) with 8GB Ram with 64 bit windows 7 Do you think I'll see a noticable improvement over what I'm seeing now, with Mapl 13. Thanks LR

## Rossler System, Further investigation: c...

This is an update to my earlier post on the Rossler system, one of the simplest examples of a dynamical system in 3 dimensions that can exhibit deterministic chaos.

restart;

interface(displayprecision=10):

PDEtools:-declare(prime=t,quiet):

ross_x:=diff(x(t),t)=-y(t)-z(t):

ross_y:=diff(y(t),t)=x(t)+a*y(t):

ross_z:=diff(z(t),t)=b+x(t)*z(t)-c*z(t):

rossler_sys:=ross_x,ross_y,ross_z;

#Find fixed points:

Maple
So it appears that using subscripts in Maple is not a good idea. I ran into this problem for the first time yesterday, and is documented here: http://www.mapleprimes.com/forum/drivenharmonicoscillatoramplitudephaseangle#comment-32780 And now it seems I've run into it again. Or possibly I have made a mistake ;) This is part of an implementation of Newton-Cotes method of numerical integration: restart: NCcoef := proc(N::integer) # procedure returns the Newton-Cotes coefficients for an # appoximation with N+1 points local a,c,p,h,B,LH,RH,eq,seqeq,seqco: h := B/N:

## Rossler system, initial investigation...

Maple

Here is the Rossler system, one of the simplest examples of 3 dimensional deterministic chaos (under certain conditions according to "params"). Thanks to Doug and Joe for various assists. Comments and critiques most welcome !

restart;
interface(displayprecision=10):
ross_x:=diff(x(t),t)=-y(t)-z(t):
ross_y:=diff(y(t),t)=x(t)+a*y(t):
ross_z:=diff(z(t),t)=b+x(t)*z(t)-c*z(t):
rossler_sys:=ross_x,ross_y,ross_z;

#Find fixed points:
sol:=solve({rhs(ross_x...

## Simple rocket model...

Here's a simple rocket model

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