**Name**

**area** Compute the (algebraic) area of a curve (Dlist)

**Command Synopsis**

**area** *in* *.*

in: input curve (Dlist)

. (screen output) : result (double)

**Function Summary**

double area (in )

Dlist in ;

**Description**

This module computes the algebraic area of a curve
*P*_{1}*P*_{2}...*P*_{n}
(Dlist), viewed as a closed polygon
*P*_{1}*P*_{2}...*P*_{n}*P*_{1}. Thus, it computes

area(*P*_{1}*P*_{2}...*P*_{n}*P*_{1}) = det(*P*_{k} - *P*_{1}, *P*_{k+1} - *P*_{1}),

with
det, = *ad* - *bc*.

The result is the area of the original curve if it is closed
(

**See Also**

**Version 1.0**

Last Modification date : Thu Nov 29 20:23:56 2001

**Author**

Lionel Moisan