curve groupings


last updated: 20051024 
Some more general groupings of curves are the following:
A closed curve is a curve with no endpoints,
so it encloses an area.
A curve that is not closed, is an open curve.
A simple curve is a curve that does not cross
itself.
A nonsimple curve does cross itself.
A Jordan curve is a curve which is
topologically equivalent to a circle.
Such a curve with a direction is called a contour.
A simple closed curve with no points of inflection is called an egg
curve.
