POLY_AREA Function

Standard Library function that returns the area of an n-sided polygon, given the vertices of the polygon.

Usage

result = POLY_AREA(x, y)

Input Parameters

x — An n-element real vector containing the x-coordinates of each vertex in the polygon.

y — An n-element real vector containing the y-coordinates of each vertex in the polygon.

Returned Value

result — The area of the polygon, returned as a floating-point value.

Keywords

None.

Discussion

POLY_AREA assumes that the input polygon has n vertices with n sides, and that the edges connect the vertices in the order [(x₁, y₁), (x₂, y₂ ), ..., (x_n, y_n), (x₁, y₁)]. The last vertex must be connected to the first.

Example 1

x = [1, 3, 2]

y = [1, 1, 4]

area = POLY_AREA(x, y)

PRINT, area

; PV-WAVE prints:  3.00000

Example 2

x = [2, 4, 4, 2]

y = [1, 1, 2, 2]

PRINT, POLY_AREA(x, y)

; PV-WAVE prints:  2.00000