Function Reference
— Function File: polyarea (x, y)
— Function File: polyarea (x, y, dim)

Determines area of a polygon by triangle method. The variables x and y define the vertex pairs, and must therefore have the same shape. They can be either vectors or arrays. If they are arrays then the columns of x and y are treated separately and an area returned for each.

If the optional dim argument is given, then polyarea works along this dimension of the arrays x and y.