Why would the vector packages need to "override" the product function?
Would it be all that hard to write functions for the dot and cross
products? Sorry if I am asking a lot of questions that may seem silly,
but I am curious.
-Ron
----- Original Message -----
From: Barton Willis
Date: Wednesday, October 19, 2005 1:30 pm
Subject: Re: [Maxima] Vector analysis and bode plots
> maxima-admin@math.utexas.edu wrote on 10/19/2005 02:13:43 PM:
>
> > Wouldn't it possibly be better if:
> > -The vector operations were automatically loaded?
>
> No, loading vect.mac makes a mess of 'product':
>
> (%i1) product(x+k,k,1,3);
> (%o1) (x+1)*(x+2)*(x+3)
> (%i2) load("vect");
> (%o2) c:/maxima/share/maxima/5.9.2/share/vector/vect.mac
> (%i3) product(x+k,k,1,3);
> Too many arguments supplied to product(uu,pv):
> [x+k,k,1,3]
>
> > -There was an option to specify the coordinate system?
>
> This feature exists; it's incompletely documented in
> share/vect/vector.usg:
>
> (%i1) load("vect_transform");
> (%o1) c:/maxima/share/maxima/5.9.2/share/vector/vect_transform.mac
> (%i2) load("vect");
> (%o2) c:/maxima/share/maxima/5.9.2/share/vector/vect.mac
> (%i3) scalefactors(polar);
> (%o3) done
> (%i4) grad(r * cos(theta));
> (%o4) grad(r*cos(theta))
> (%i5) express(%);
> (%o5) ['diff((r*cos(theta)),r,1),'diff((r*cos(theta)),theta,1)/abs(r)]
> (%i6) %,diff;
> (%o6) [cos(theta),-(r*sin(theta))/abs(r)]
>
>
> Barton
>