13.16.1 Checking if a point is on an object in the plane: is_element
See Section 14.13.1 for checking elements in three-dimensional
geometry.
The is_element command determines whether or not a point is
on a geometric object.
-
is_element takes two arguments:
-
P, a point.
- G, a geometric object.
- is_element(P,G) returns 1 if P is an element of
G and returns 0 otherwise.
Examples.
-
Input:
is_element(-1-i, line(0,1+i))
Output:
- Input:
is_element(i, line(0,1+i))
Output: