Elliptic Features

Abstract

The procedures that are addressed in this chapter are those that generate and operate on elliptically shaped features. Such features do not represent a staple curve type in civil engineering design and construction except perhaps in (a) certain structural designs to attain special architectural effects, (b) certain storm water detention or retention pond design and architectural landscape designs to produce esthetic effects, (c) hydraulic conduit (pipe) shapes where horizontal or vertical space restriction and other requirements so dictate, and (d) at times in general drafting operations in the production of engineering design and construction drawings. The ellipse is a conical section (see Figures 11.1a and 12.1a) which together with its sisters, circle, parabola, and hyperbola, draw their name from Apollonios of Perga over 2000 years ago. For those interested in etymology of words reference is made to Volume II of A History of Mathematics by Sir Thomas Heath page 138 of the 1981 Dover publication.