Hi Jeoffrey, How stable are the results in general ? If you repeat the analysis in R several times, does it yield the same results ?
Tal ----------------Contact Details:------------------------------------------------------- Contact me: tal.gal...@gmail.com | 972-52-7275845 Read me: www.talgalili.com (Hebrew) | www.biostatistics.co.il (Hebrew) | www.r-statistics.com (English) ---------------------------------------------------------------------------------------------- On Mon, Apr 26, 2010 at 3:37 PM, Jeoffrey Gaspard < jeoffrey.gasp...@gmail.com> wrote: > Hello everyone! > > My data is composed of 277 individuals measured on 8 binary variables > (1=yes, 2=no). > > I did two similar cluster analyses, one on SPSS 18.0 and one on R 2.9.2. > The > objective is to have the means for each variable per retained cluster. > > 1) the R analysis ran as followed: > > > call data > > dist=dist(data,method="euclidean") > > cluster=hclust(dist,method="ward") > > cluster > > Call: > hclust(d = dist, method = "ward") > > Cluster method : ward > Distance : euclidean > Number of objects: 277 > > > plot(cluster) > > rect.hclust(cluster, k=4, border="red") > > x=rect.hclust(cluster, k=4, border="red") > > sapply(x, function(i) colMeans(data[i,])) > > round(sapply(x, function(i) colMeans(data[i,])),2) > > 2) The SPSS analysis ran as follows: > > Analysis --> Classify --> Hierarchical cluster analysis --> Cluster method= > Ward's method and Distance measure= Interval: Squared Euclidean distance. > After that, I computed the means of each variable for each cluster. > > The problem is I have different results between the two analyses (different > clusters and means). > > However, when I use the "Euclidean distance" (unsquared) in SPSS, I have > the > same results! > > I thought the R "euclidean" command meant the "usual square distance > between > the two vectors (2 norm)" as specified in the documentation, no the > unsquared distance. Did it not? > > Thanks for the comment! > > Jeffrey > > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
