(49g 50g) Shoelace algorithm

[John Keith]

At Albert Chan's request, I am posting an HP-48G / HP 50 program for the perimeter of a polygon. Stack diagram is the same as for Thomas's programs for polygon area and centroid:

xs ys -> p

Code:


\<< R\->C DUP HEAD + 2.
  \<< - ABS
  \>> DOSUBS \GSLIST
\>>