## CGAL::compare_y_at_x

Comparison_result | compare_y_at_x ( Point_2<Kernel> p, Line_2<Kernel> h)
|  | compares the y-coordinates of p and the vertical projection of p on h, see (d) in the figure below. Precondition: h is not vertical.

Comparison_result

compare_y_at_x ( | Point_2<Kernel> p, Line_2<Kernel> h1, Line_2<Kernel> h2)

|  | compares the y-coordinates of the vertical projection of p on h1 and on h2, see (e) in the figure below. Precondition: h1 and h2 are not vertical.

Comparison_result

compare_y_at_x ( | Line_2<Kernel> l1, Line_2<Kernel> l2, Line_2<Kernel> h)

|  | Let p be the intersection of lines l1 and l2. This function compares the y-coordinates of p and the vertical projection of p on h, see (f) in the figure below. Precondition: l1, l2 intersect and h is not vertical.

Comparison_result

compare_y_at_x ( | Line_2<Kernel> l1, Line_2<Kernel> l2, Line_2<Kernel> h1, Line_2<Kernel> h2)

|  | Let p be the intersection of lines l1 and l2. This function compares the y-coordinates of the vertical projection of p on h1 and on h2, see (g) in the figure below. Precondition: l1 and l2 intersect; h1 and h2 are not vertical.

Comparison_result

compare_y_at_x ( | Point_2<Kernel> p, Segment_2<Kernel> s)

|  | compares the y-coordinates of p and the vertical projection of p on s. If s is vertical, then return EQUAL when p lies on s, SMALLER when p lies under s, and LARGER otherwise. Precondition: p is within the x range of s.

Comparison_result

compare_y_at_x ( | Point_2<Kernel> p, Segment_2<Kernel> s1, Segment_2<Kernel> s2)

|  | compares the y-coordinates of the vertical projection of p on s1 and on s2. If s1 or s2 is vertical, then return EQUAL if they intersect, otherwise return SMALLER if s1 lies below s2, and return LARGER otherwise. Precondition: p is within the x range of s1 and s2.

### See Also

CGAL::compare_xy
CGAL::compare_xyz
CGAL::compare_x
CGAL::compare_x_at_y
CGAL::compare_y
CGAL::compare_yx
CGAL::compare_z