Possibility/ease of doing some vector ops in Maxima

Hi

tellsimp() or tellsimpafter don't work for me in this case
the one possibility is to use subst(del(p),0,expr) and another way is
via defrule-apply1
(C23) defrule(delp,del(p),0);
(D23)                         delp : DEL(p) -> 0
(C24) f : diff(L_1*L_2*(L_1-L_2)^(p-1));
                                    p - 1
(D24) L_1 LOG(L_1 - L_2) (L_1 - L_2)      L_2 DEL(p)

                   p - 1                  p - 2
 + (L_1 (L_1 - L_2)      - L_1 (L_1 - L_2)      L_2 (p - 1)) DEL(L_2)

                   p - 2                          p - 1
 + (L_1 (L_1 - L_2)      L_2 (p - 1) + (L_1 - L_2)      L_2) DEL(L_1)
(C25) apply1(%,delp);
                      p - 1                  p - 2
(D25) (L_1 (L_1 - L_2)      - L_1 (L_1 - L_2)      L_2 (p - 1)) DEL(L_2)

                             p - 2                          p - 1
           + (L_1 (L_1 - L_2)      L_2 (p - 1) + (L_1 - L_2)      L_2)DEL(L_1)

> Hi Barton
>
> On Thu, 2002-09-19 at 03:00, willisb@unk.edu wrote:
> > Instead of grad, try using diff without a second argument.
> > Used this way, diff works like a total derivative operator:
> >
> >    diff(f(x,y)) = diff(f(x,y),x) * del(x) + diff(f(x,y),y) * del(y).
> >
> > First, tell Maxima that del(p) is zero.
> >
> > (C1) tellsimpafer(del(p),0);
> > (D1) tellsimpafer(DEL(p),0)
> >
> > Second, compute the total derivative
> >
> > (C2) f : diff(L_1*L_2*(L_1-L_2)^(p-1));
> > (D2) (L_1*(L_1-L_2)^(p-1)-(p-1)*L_1*(L_1-L_2)^(p-2)*L_2) * DEL(L_2)
> >       +((L_1-L_2)^(p-1)*L_2+(p-1)*L_1*(L_1-L_2)^(p-2)*L_2)*DEL(L_1)
>
> When I try this, I get the following:
>
> (C309) tellsimpafer(del(p),0);
> (D309) 					        tellsimpafer(DEL(p), 0)
> (C310) f : diff(L_1*L_2*(L_1-L_2)^(p-1));
> L_1*LOG(L_1-L_2)*(L_1-L_2)^(p-1)*L_2*DEL(p)+(L_1*(L_1-L_2)^(p-1)-
> L_1*(L_1-L_2)^(p-2)*L_2*(p-1))*DEL(L_2)+(L_1*(L_1-L_2)^(p-2)*L_2*(p-1)+
> (L_1-L_2)^(p-1)*L_2)*DEL(L_1)
>
> I assume the tellsimpafer command is not doing quite the right thing?
>
> Thanks
> Neilen
>
> > If you want grad instead of del, use subst
> >
> > (C3) f : subst(grad,del,f);
> > (D3) (L_1*(L_1-L_2)^(p-1)-(p-1)*L_1*(L_1-L_2)^(p-2)*L_2) * GRAD(L_2)
> >       +GRAD(L_1)*((L_1-L_2)^(p-1)*L_2 +(p-1)*L_1*(L_1-L_2)^(p-2)*L_2)
> >
> > To extract the coefficients of grad(L_1), etc, use expand followed
> > by coeff
> >
> > (C4) f : expand(f);
> > (D4) -p*L_1*(L_1-L_2)^(p-2)*L_2*GRAD(L_2)
> >       +L_1*(L_1-L_2)^(p-2)*L_2*GRAD(L_2)
> >       +L_1*(L_1-L_2)^(p-1)*GRAD(L_2)
> >       +GRAD(L_1)*(L_1-L_2)^(p-1)*L_2
> >       +p*L_1*GRAD(L_1)*(L_1-L_2)^(p-2)*L_2
> >       -L_1*GRAD(L_1)*(L_1-L_2)^(p-2)*L_2
> > (C5) [coeff(f, grad(L_1)), coeff(f,grad(L_2))];
> >
> > (D5) [(L_1-L_2)^(p-1)*L_2+p*L_1*(L_1-L_2)^(p-2)*L_2
> >                    -L_1*(L_1-L_2)^(p-2)*L_2,
> >       -p*L_1*(L_1-L_2)^(p-2)*L_2+L_1*(L_1-L_2)^(p-2)*L_2
> >                         +L_1*(L_1-L_2)^(p-1)]
> > (C6)
> >
> >
> > Maybe this helps?
> >
> > Barton
> >
> >
> >
> >
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