Node: Returning Elements and Information for Ellipses, Next: Ellipse Intersections, Previous: Querying Ellipses, Up: Ellipse Reference
Point& get_center (void )

Virtual function 
Point get_center (void )

const virtual function 
These functions return center .

const Point& get_focus (const unsigned short s)  Function 
Point get_focus (const unsigned short s)  const function 
These functions return focus0 or focus1 , depending on the
value of s, which must be 0 or 1. If s is not 0 or 1,
get_focus() returns INVALID_POINT .

real get_linear_eccentricity (void)  const function 
Returns linear_eccentricity .

real get_numerical_eccentricity (void)  const function 
Returns numerical_eccentricity .

real get_axis_v (void )

Function 
real get_axis_v (void )

const function 
Calculates and returns the value of axis_h .
If the 
real get_axis_h (void )

Function 
real get_axis_h (void )

const function 
Calculates and returns the value of axis_h .
If the 
signed short location (Point p)  const virtual function 
Returns a value l indicating the location of the Point argument
p with respect to the Ellipse .
Let e stand for the
Ellipse e(origin, 3, 5, 45, 15, 3); e.shift(2, 1, 1); Point A = e.get_point(7); cout << e.location(A);  0 Point B = center.mediate(e.get_point(2)); cout << e.location(B);  1 Point C = center.mediate(e.get_point(2), 1.5); cout << e.location(C);  1 Point D = A; D.shift(2, 0, 4); e.location(D);  WARNING! In Ellipse::location(): Point doesn't lie in plane of Ellipse. Returning 2. e.scale(1.5, 0, 1.5); e.location(A);  WARNING! In Ellipse::do_transform(const Transform&): This transformation has made *this nonelliptical! ERROR! In Ellipse::location(): Ellipse is nonelliptical. Returning 3.

Point angle_point (real angle)  const function 
Returns a point on the Ellipse given an angle.
A Point p is set to the zeroth Point on the Ellipse
and rotated about the line from the center of the Ellipse in the
direction of the normal to the plane of the Ellipse .
Then, the intersection of the ray from the center through
p and the perimeter of the Ellipse is returned.
Ellipse e(origin, 6, 4); Point P = e.angle_point(135); current_picture.output(Projections::PARALLEL_X_Z);
[next figure] demonstrates, that the rotation is unfortunately not always in the direction one would prefer. I don't have a solution to this problem yet. Ellipse e(origin, 6, 4, 90); Point P = e.angle_point(135); Point Q = e.angle_point(135);
