I meant: p1.set_vel(N, u1 * N.x)
Jason moorepants.info +01 530-601-9791 On Mon, Jan 12, 2015 at 10:08 AM, Jason Moore <[email protected]> wrote: > Some notes: > > - Since you specified your kinematic relations as u = q', then you should > set your velocities with u instead of q, for example: p1.set_vel(N, u1d * > N.x) > - I doubt that you need to specify any velocity constraints and thus you > will not have any dependent speeds. You've defined ell as some new > coordinate, but do not add it as an independent coordinate. I don't think > this is correct. It will likely work if you just remove the coordinate > constraint stuff. > > > Jason > moorepants.info > +01 530-601-9791 > > On Mon, Jan 12, 2015 at 5:12 AM, Guillaume Gay <[email protected]> wrote: > >> >> Hi, >> >> I'm trying to use sympy KanesMethod to model biological assemblies (i.e. >> the mitotic spindle). >> >> Molecular motors in biology follow linear force velocity relationships, >> such that F = F_max(1 -ld/V_max) where ld is the relative speed of the two >> points on which the force is applied (distant of l). >> >> I strugle to implement this in the Kanes formalism... I tried various >> things: >> * constraint the generalized speed as u = (V_max - ld) >> * declare the above relation in the kinetic differential equation >> >> In both cases, the `to_linearizer` method rises a: >> >> ValueError: Cannot have dynamicsymbols outside dynamic forcing vector. >> >> * use directly ld as the speed, and declare it as auxiliary >> >> Then I have a shape mismatch when I try to linearize. >> >> Bellow is a notebook with the code: >> >> http://nbviewer.ipython.org/github/glyg/Notebooks/blob/ >> master/kt_sim/minimum%20Linear%20Force%20Velocity.ipynb >> >> >> Best, >> >> Guillaume >> >> -- >> Guillaume Gay, PhD >> >> http://damcb.com >> >> 43 rue Horace Bertin >> 13005 Marseille >> >> +33 953 55 98 89 >> +33 651 95 94 00 >> >> n°SIRET 751 175 233 00020 >> >> -- >> You received this message because you are subscribed to the Google Groups >> "sympy" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/sympy. >> To view this discussion on the web visit https://groups.google.com/d/ >> msgid/sympy/54B3C853.5090405%40gmail.com. >> For more options, visit https://groups.google.com/d/optout. >> > > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAP7f1AhCfvka0rhDA3%2BuboCbk-8e3eWF8yHQaJYUQZ%2B6w%3DV_jA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
