The J%JOIN Package

Abstract

The J%JOIN program creates links between the elements of a set of line segments on the basis of their geometric proximity. According to the value of the third argument, (T or NIL), the program will either place a set of links in an array, suitable for use by the program P%PURPOSE, or will return a set of "re-adjusted" line segments with the property that lines apparently converging on a common vertex are assigned identical end points at the appropriate ends. Twelve geometric parameters are used to control the joining procedure. Starred sections (*) are for reference only; J%JOIN may be successfully used by someone familiar with only the unstarred sections of this memo.