26.11.1 Ellipse in the plane
For ellipses in space, see Section 27.9.2.
The ellipse
command draws ellipses and other conic sections.
ellipse can take parameters in two different ways.
-
ellipse can take one argument:
eqn, a second degree equation in the variables x
and y (or an expression which will be set to zero).
- ellipse(eqn) returns and draws
the conic section given by eqn.
- Alternatively, ellipse can take three arguments:
-
A,B, two points.
- C, a point or a real number.
- ellipse(A,B,C) returns and draws the ellipse with
foci A and B and passing through C (if C is a point) or
whose semi-major axis has length C (if C is a real number).
- Note that if the third argument is a point on the real axis, the
real affix of the point won’t work, it needs to be specified with
the point command.
Examples