stuck with vectors



-----maxima-bounces at math.utexas.edu wrote: -----

>First question:  should I declare x somehow to be
>a vector, or does the next line do so by using x[1], x[2], x[3]?

There is no need to declare x to be a vector. Maxima doesn't
have a vector data structure---just lists, matrices, and arrays.

>xprime:(1+RR) * (1-RR) . P1 + (1+RR) . P2 + 2 *
>(1-RR) * SQ . matrix ([x[1]],[x[2]],[x[3]]);

I think you used "." twice for scalar times column vector.
Instead of "." (non commutative multiplication), you need "*"
(commutative multiplication). Something like:

(1+RR) * (1-RR) * P1 + (1+RR) . P2 + 2 * (1-RR) * SQ * matrix
([x[1]],[x[2]],[x[3]]);

After that, expand will expand 'mm' into a (giant) scalar.

Barton