On Wed, 2006-04-19 at 07:46 +0100, Prof Brian Ripley wrote: > Short answer: you cannot compare distances including NAs, so there is no > way to find a monotone mapping of distances. > The original Kruskal-Young-Shepard-Torgerson programme KYST (version 1 from 1973) could handle missing values. Unfortunately I've lost the documents, but if I remember correctly, the argument was that you don't need but a subset (representative for points) of (dis)similarities to get a monotone regression. KYST -- and computers of that time (I used Burroughs!) -- had limitations on data size, and removing some of the dissimilarities was a way of getting more than 64 data points into analysis. However, better not go into details since:
C THIS INFORMATION IS PROPRIETARY AND IS THE C PROPERTY OF BELL TELEPHONE LABORATORIES, C INCORPORATED. ITS REPRODUCTION OR DISCLOSURE C TO OTHERS, EITHER ORALLY OR IN WRITING, IS C PROHIBITED WITHOUT WRITTEN PRERMISSION OF C BELL LABORATORIES. C KYST-2A AUGUST, 1977 cheers, jari oksanen -- Jari Oksanen -- Biologian laitos, Oulun yliopisto, 90014 Oulu sposti [EMAIL PROTECTED], kotisivu http://cc.oulu.fi/~jarioksa/ ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html