Would be nice if someone posted the Lorenz attractor code on planet.sagemath.org!
For those who don't subscribe to this list... Fabio On Jan 29, 2008 8:32 PM, mhampton <[EMAIL PROTECTED]> wrote: > > We really need to get xpp and/or AUTO into sage at some point. I have > made some half-hearted stabs at it but have lacked the time to get > serious. Like R support, its a chicken-and-egg problem: without real > users within the sage community, it doesn't get put in, and until its > in right there aren't any real users. I am very happy that R has been > included, the interface can now be polished. We need to kick start > the dynamical systems components. > > cheers, > Marshall > > On Jan 29, 6:17 am, "David Joyner" <[EMAIL PROTECTED]> wrote: > > That's cool. Good luck on your talk. > > > > BTW, have you tried this?http://www.math.pitt.edu/~bard/xpp/xpp.html > > I could not get it to compile from source but fortunately > > is a debian package (apt-get install xppaut). The docs say it > > > > "is a tool for solving > > > > * differential equations, > > * difference equations, > > * delay equations, > > * functional equations, > > * boundary value problems, and > > * stochastic equations." > > > > So I thought you might be interested. The screenshot > > section even has an animated > gifhttp://www.math.pitt.edu/~bard/xpp/ss/screen.html > > Lorentz plot. > > > > On Jan 29, 2008 4:38 AM, Joshua Kantor <[EMAIL PROTECTED]> wrote: > > > > > > > > > I was preparing a talk on solving ODE's in sage, and the culminating > > > example is pretty neat so I thought I would post it. > > > > > The following code will plot a little bit of the lorenz attractor > > > > > sage: def lorenz(t,y,params): > > > ... return [params[0]*(y[1]-y[0]),y[0]*(params[1]-y[2])- > > > y[1],y[0]*y[1]-params[2]*y[2]] > > > > > sage: def lorenz_jac(t,y,params): > > > ... return [ > [-params[0],params[0],0],[(params[1]-y[2]),-1,-y[0]], > > > [y[1],y[0],-params[2]],[0,0,0]] > > > sage: T=ode_solver() > > > sage: T.algorithm="bsimp" > > > sage: T.function=lorenz > > > sage: T.jacobian=lorenz_jac > > > sage: T.ode_solve(y_0=[. > > > 5,.5,.5],t_span=[0,155],params=[10,40.5,3],num_points=4000) > > > sage: l=[T.solution[i][1] for i in range(len(T.solution))] > > > sage: line3d(l,thickness=2) > > > > > This is somewhat computationally intensive (takes around a minute). > > > > > I thought the plot was quite neat. > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
