Calling all knights of the lambda

[mt8891]

i'm really going nuts here. I don't know much about lisp. however, I do know a thing or two about C. Knowing a lot about C and trying to learn lisp is like (to me) trying to learn italian when completely wasted out of your mind whilst taking a trip to italy but speaking fluent english anyway. Anyway, I'm attempting to write a couple of elementary linear algebra equations into lisp.

example 1:

i have my crossproduct function as:

(defun crossprod (v1 v2 v3 u1 u2 u3)
(list
(- (* v2 u3) (* v3 u2))
(*-1 (- (*v1 u3) (* v3 u1)))
(- (*v1 u2) (* v2 u1))))

and I mean it works fine and I've got no issues with it...if you like it go ahead and use it but there is something that tells me wait. I want to be able to use VECTORS as lists ie the vector 1,-5,8 or 6,-6,6 but of course in lisp it would be some sort of form like (1 -5 8) or (6 -6 6) and I can't seem to get how to say something like

(split vector1 vector2)
where I can use the i j k's of each vector in some other function or whatever. etc.anyway, I am more curious about a normalize-ing deal that I can use vector inputs (as lists). at the base of it all how can I smash up lists and use them in sequence so I dont, for instance, have to say: (first vector1) (second vector2) (third vector3) etc...

I'll admit I could mix and match c and this stuff only because I know loops in C(but I don't mean really I mean conceptually in my noggin, what, you never thought it'd be easy searing for those red mushrooms from mario in grandtheft auto?). I don't know loops about lisp too well. anyone who as any algorithms..let me know. thanks-mt

 

[Future Bruno]

You can use the LOOP macro in Lisp to iterate over elements of a list. Here is an example:(defun normalize-vector (vector) (let ((sum 0)) (loop for element in vector do (incf sum (* element element))) (loop for element in vector collect (/ element (sqrt sum)))))This function will take a vector (list) as input and normalize it. The first loop calculates the sum of the squares of the elements of the vector, and the second loop divides each element by the square root of the sum in order to normalize it.