(49g 50g) Shoelace algorithm

[Thomas Klemm]

(08-24-2018 03:56 AM)Thomas Klemm Wrote:  There might be better ways to rotate the elements of ys left and right.

(xs ys -- area)

Code:

« DUP SIZE → xs ys s
  « ys OBJ→ ROLLD s → LIST
    ys OBJ→ ROLL s →LIST
    - xs * ΣLIST 2 /
  »
»

I've read somewhere that it's faster to do the rotation on the stack.

Cheers
Thomas