POLYAREA

Purpose:

Calculates the area of a closed loop series.

Syntax:

POLYAREA(series)

series

-

Optional. A series. Defaults to the current Window.

Alternate Syntax:

POLYAREA(xseries, yseries)

xseries

-

Optional. A series. Defaults to the X values of the current Window.

yseries

-

Optional. A series. Defaults to the Y values of the current Window.

Returns:

A scalar, the closed polygon area..

Example:

W1: gsin(6, 1, 1/5)

W2: gcos(6, 1, 1/5)

W3: xy(w1, w2)

W4: {polyarea(w3)}

 

W3 contains a regular pentagon. W4 contains the value 2.377641, the approximate area of the pentagon.

Example:

f := 6;

 

W1: gsin(f+1, 1, 1/f)

W2: gcos(f+1, 1, 1/f)

W3: xy(w1, w2)

W4: {polyarea(w3)}

 

W3 contains a regular hexagon parameterize by the hot variable f.  W4 contains the value 2.598076, the approximate area of the hexagon.

 

f = 8;

 

Changing f to 8 creates an octagon in W3 with the area calculated in W4 as 2.828427.

Example:

f := 6;

 

W1: gsin(f+1, 1, 1/f)

W2: gcos(f+1, 1, 1/f)

W3: {polyarea(w1, w2)}

 

Same as the previous example except the X and Y values

Remarks:

POLYAREA expects a closed polygon and automatically adds the closing point if the starting point does not equal the ending point.

 

See CAREA to compute the area of an arbitrary closed loop curve.

See Also:

AREA

CAREA

CUMTRAPZ

INTEG

TRAPZ