Path: utzoo!utgpu!watserv1!watmath!att!bellcore!rutgers!cs.utexas.edu!usc!apple!vsi1!zorch!xanthian From: xanthian@zorch.SF-Bay.ORG (Kent Paul Dolan) Newsgroups: comp.graphics Subject: Re: Scattered Data -> Regular Grid Data Keywords: Scattered , Data , Regular Message-ID: <1990Jun16.010537.17448@zorch.SF-Bay.ORG> Date: 16 Jun 90 01:05:37 GMT References: <1990Jun15.122858.1197@jarvis.csri.toronto.edu> <1990Jun16.004234.17224@zorch.SF-Bay.ORG> Organization: SF Bay Public-Access Unix Lines: 29 In article <1990Jun16.004234.17224@zorch.SF-Bay.ORG> xanthian@zorch.SF-Bay.ORG (Kent Paul Dolan) writes: >In article <1990Jun15.122858.1197@jarvis.csri.toronto.edu> corkum@csri.toronto.edu (Brent Thomas Corkum) writes: >>I'm looking for some references or comments concerning the conversion >>of scattered data in two dimensions to data on a regular grid. I would >>alos like to be able to handle holes in the data, meaning areas in which >>no interpolation or extrapolation will occur or cross. But this last >>requirement is not mandatory. Sorry about following up my own posting, I'm not usually this lazy. The triangulation described in the following, if accomplished by first enclosing the whole data set in a very large triangle whose points have the average value of the data set, (or perhaps lie on a plane which is a least squares fit to the data) allows reasonable assignment of points to a regular grid covering the same area, and stable extrapolation within the area covered by the circumscribing triangle. Automated Contour Mapping Using Triangular Element Data Structures and An Interpolant Over Each Irregular Triangular Domain by C. M. Gold, University of Alberta, T. D. Charters, Alberta Environment, and J. Ramsden, Alberta Research Page 170-175 in: Computer Graphics, A Quarterly Report of SIGGRAPH-ACM, Volume 11, Number 2, Summer 1977, a.k.a. SIGGRAPH '77 Proceedings. This is a very approachable paper, though I'd like to see where Chris has gone with this material since 1977. Kent, the man from xanth.