On Tue, 2009-04-07 at 20:16 -0400, Neal Becker wrote: > On Tuesday 07 April 2009, Riccardo Gori wrote: > > 2009/4/7 flyeng4 <flye...@gmail.com> > > > > > I am trying to understand physics.units. Here is an ipython session > > > illustrating my mental block > > > > > > In [32]: from sympy.physics.units import * > > > > > > In [33]: V/ohm > > > Out[33]: A <-- This makes sense. > > > > > > In [34]: A*ohm > > > Out[34]: m**2*kg/(A*s**3) <-- Why not 'V'? > > > > > > In [35]: V/A > > > Out[35]: m**2*kg/(A**2*s**3) <-- Why not 'ohm'? > > > > > > In [36]: W/A > > > Out[36]: m**2*kg/(A*s**3) <-- Why not 'V'> > > > > > > In [37]: V/ohm > > > Out[37]: A <-- Again this makes sense. > > > > > > In [38]: W/V > > > Out[38]: A <-- This makes sense. > > > > > > In [40]: 1/s > > > Out[40]: 1/s <-- Makes sense but might be 'hz'? > > > > > > In [42]: sympy.__version__ > > > Out[42]: '0.6.4.beta1' > > > > > > Can someone explain this behavior and maybe shed some light on how I > > > could get this to work the way that I think it should? > > > > > > Thanks, > > > Bill > > > > Hello Bill, > > I think it's because sympy uses the international system of units, look at: > > > > http://en.wikipedia.org/wiki/SI#Units > > > > Umm, maybe I'm missing something here, but if V/Ohm -> A, then A*Ohm-> V. > What's that got to do with SI Units?
one weird thing is that A is a base unit, while C is derived. so when it prints everything as SI base units, A is correct, not C/s. > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sympy?hl=en -~----------~----~----~----~------~----~------~--~---
