ok i see so that is just a shortcut way to make a matrix.

I thought I understood, but then I tried this:

Mint:=<<ax | 0 | ox>, <0 | ay | oy>, <0 | 0 | 1>>

and it says "Error, invalid function argument delimiters." It looks exactly like the example in the help - what is the difference?

Dave

whoa - what is the <> vs Matrix() ?

also, I'm assuming ^%T is transpose? so <.,.,.> is always a column vector? I though Transpose() was to transpose?

That worked though - so it keeps me going for now!

Dave

I'm not a math guy, i'm just an engineer!  I dont need to do abstract linear algebra, i just need to make it so that things like

Transpose(x)*A*x

dont turn into (x^2 * A).

I just have alot of big Hessian matrices to find and I don't want to do them by hand.  Surely there is a way to do this, maybe I am not explaining clearly?

As a simple example,

F=x^T*A*x

diff(F,x) should equal x^T * (A^T + A)

of course if I do:

F:=x*A*x

diff(F,x) gives me 2*x*A, which is not what I need.

Please let me know.

Thanks!

Dave