home *** CD-ROM | disk | FTP | other *** search
/ NetNews Usenet Archive 1992 #19 / NN_1992_19.iso / spool / comp / programm / 2528 < prev    next >
Encoding:
Text File  |  1992-08-29  |  1.6 KB  |  33 lines
  1. Newsgroups: comp.programming
  2. Path: sparky!uunet!usc!sdd.hp.com!news.cs.indiana.edu!umn.edu!thompson
  3. From: thompson@atlas.socsci.umn.edu (T. Scott Thompson)
  4. Subject: Re: How to decide if a point is inside a polygon?
  5. Message-ID: <thompson.715056569@malthus.econ.umn.edu>
  6. Sender: news@news2.cis.umn.edu (Usenet News Administration)
  7. Nntp-Posting-Host: malthus.econ.umn.edu
  8. Reply-To: thompson@atlas.socsci.umn.edu
  9. Organization: Economics Department, University of Minnesota
  10. References: <7121@bigbird.hri.com.hri.com> <schnitzi.714934670@eola.cs.ucf.edu> <1992Aug27.153902@is.morgan.com> <schnitzi.715017774@eola.cs.ucf.edu> <1992Aug28.134203@is.morgan.com> <schnitzi.715032142@eola.cs.ucf.edu>
  11. Date: Sat, 29 Aug 1992 02:49:29 GMT
  12. Lines: 19
  13.  
  14. schnitzi@cs.ucf.edu (Mark Schnitzius) writes:
  15.  
  16. >You are right; sorry, I misunderstod your earlier point.  So how can we
  17. >get this to work for all cases?  Just find a direction to extend the
  18. >infinite line that doesn't intersect any vertices?
  19.  
  20. Not a good idea.  Choosing a new direction means starting over and
  21. wasting your previous calculations.  There are ways to fix up the
  22. "vertex" and "colinear edge" problems without having to choose a new
  23. direction.
  24.  
  25. For details, look at the thread on this same topic on the newsgroup
  26. sci.math that gives specific references to some methods that deal with
  27. the various things that can go wrong.  (The original question was also
  28. posted to that group.)
  29. --
  30. T. Scott Thompson              email:  thompson@atlas.socsci.umn.edu
  31. Department of Economics        phone:  (612) 625-0119
  32. University of Minnesota        fax:    (612) 624-0209
  33.