Carl, this is certainly reasonable, but maybe a little unfeasible. The reason is that, I use some scripts of mine in the process of the evaluation, and the whole process is pretty long.
The algorithm basically starts from a couple of linear systems of equations; they are solved, and from the solution is derived the (averaged) state space representation of the system, in terms of: dx/dt = A*x + B*u y = C*x + B*u Then, the matrices are combined to get the matrix of input-to-state and input-to-output transfer functions (in the Laplace transform domain) as: x/u = (s*I - A)**(-1)*B y/u = C*(s*I - A)**(-1)*B + D So, the G_igr_d (the function initially shown), is one element of this matrix. As you can see, the process is not particularly complex, but a bit long, and that would oblige me to upload some custom scripts as well. Can you derive some information from this description, or has this been useless? Maybe I can provide something like the last part of the notebook, placing some intermediate expression by hand. Could you also show me where should I look at for better understanding this? Is it a good idea to verify the types of the expressions used? Is it a problem interfacing to any symbolic package different from the ordinary maxima one? I don't exactly recall if I took advantage of others. Thanks Maurizio On Feb 25, 9:17 pm, Carl Witty <carl.wi...@gmail.com> wrote: > On Wed, Feb 25, 2009 at 11:05 AM, Maurizio <maurizio.gran...@gmail.com> wrote: > > So I manually write down the same expression in a new variable, I get: > > > time dizTemp = temp.subs(paramsd) > > Time: CPU 0.01 s, Wall: 0.01 s > > > And temp and G_igr_d have the same type!! > > > Where can the lag arise from? This seems really subtle to me! > > Please note that the expression is coming from some matrix > > combinations and then extraction > > Maybe you could publish a notebook worksheet, or attach a script, > showing a complete worked example to demonstrate the slowness? > > Carl --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
