Ellipse explicitly defined

Syntax: | `ELLIPSE a b xc yc angle ELLIPSE\POPULATE a b xc yc angle ELLIPSE\POPULATE\NPTS a b xc yc angle n ELLIPSE\POPULATE\XYOUT a b xc yc angle xout yout ELLIPSE\POPULATE\XYOUT\NPTS a b xc yc angle n xout yout`

By default, the input parameters are assumed to be scalars representing the major axis radius, `a`, the minor axis radius, `b`, the coordinates of the centre, `cx` and `cy`, and the angle of the ellipse, `angle`, in degrees, measured counter-clockwise from the horizontal.

### Parameter order

The order in which the qualifiers appear is irrelevant. The order in which the command parameters appear is fixed: `a b xc yc angle { npts } { xout yout }`

Number of points
Fit an ellipse