[Maxima] matrix multiplication
robert.dodier at gmail.com
Thu Mar 22 13:48:47 CDT 2007
On 3/22/07, Ryan Krauss <ryanlists at gmail.com> wrote:
> Update: this code works until I load the vect package:
> (%i5) R2.cv;
> (%o5) matrix([-sin(th)],,[cos(th)])
> (%i6) load("vect");
> (%o6) /usr/local/share/maxima/5.11.0/share/vector/vect.mac
> (%i7) R2.cv;
> incompatible dimensions - cannot multiply
> -- an error. To debug this try debugmode(true);
> I need to be able to do cross products and multiply matrices in a
> compatible way. How can I do this? i.e. is there a way to do cross
> products without loading the vect package or a way to get around the
> vect package messing up dot?
vect.mac declares "." to be commutative. I believe this is to
make "." act as the scalar product of vectors (which is commutative).
Probably vect.mac should declare a different operator, say "dot"
or something, instead of changing a built-in operator.
vect's effect on "." has caused trouble before. I don't remember if
we came to any conclusions about it. I don't have any specific
advice at the moment, but that's the root of the problem here.
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