Update: this code works until I load the vect package:
(%i5) R2.cv;
(%o5) matrix([-sin(th)],[0],[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?
Thanks,
Ryan
On 3/22/07, Ryan Krauss <ryanlists at gmail.com> wrote:
> I am having trouble with matrix multiplication and I don't understand
> what the problem is. I want to multiply a 3x3 matrix bya column
> vector, and I can't seem to make it work.
>
> Specifically, I have a function defined:
> Ry(thy):=matrix([cos(thy),0,-sin(thy)],[0,1,0],[sin(thy),0,cos(thy)])$
>
> I call
> R2:Ry(th);
>
> and then I try and create a column vector:
> cv:matrix([0],[0],[1]);
>
> and try
> R2.cv;
>
> and I get the message that the dimensions are incompatible.
>
> What am I doing wrong? R2 appears to be 3x3 on the screen and cv
> displays as a 3x1.
>
> Thanks,
>
> Ryan
>