On Thu, Jun 25, 2009 at 1:59 PM, David
Ronis<ronis at ronispc.chem.mcgill.ca> wrote:
> setting v=0, which I did by ev(%, v[1]=0, v[2]=0); ?To my surprise, v
> still appears in the result. ?Is this a bug, or am I missing something?
Well, this isn't exactly a bug, but it is a deficiency in Maxima's
binding mechanism. Only a symbol can be bound, not a
subscripted variable. I think Maxima should treat subscripted
variables just like unsubscripted ones, so that's a wart.
ev attempts to work around that by substituting for subscripted
variables instead of binding them. (Hmm -- another irregularity
in ev; there certainly are a lot of them.) Looks like the substitution
is too early to help in this case. Try ev(''f, v[1]=0, v[2]=0) instead.
> What's interesting is that
>
> ev(f,v=[0,0]);
>
> does what you'd expect.
Yeah -- v is an atom, not subscripted, so it's bound.
Hope this helps,
Robert Dodier