On 16.11.2009 19:13, Charles C. Berry wrote: >> The question: Can this be accomplished in the *dendrogram plot* >> by manipulating the resulting hclust data structure or by some >> other means, and if yes, how? > > Yes, you need to study > > ?hclust > > particularly the part about 'Value' from which you will see what needs > modification. > > Here is a very simple example: > >> res <- hclust(dist(1-diag(3)*rnorm(3))) >> plot(res) >> res2 <- res >> res2$merge <- rbind(-cbind(1:3,4:6), matrix(ifelse( res2$merge<0, >> -res2$merge, res2$merge+sum(res2$merge<0)),2)) >> res2$height <- c(rep(0,3), res2$height) >> res2$order <- as.vector( rbind(res2$order,(4:6)[res2$order]) ) >> plot(res2) >> str( res ) >> str( res2 )
Dear Chuck, Many thanks for spending your valuable time in the suggestions and the example. However, the drawback is that as a humanist I have been having considerable difficulties in figuring out what exactly to do. After hours of experimenting I could modify another dendrogram (without crashing R), but still fail to get the result I want to: the added leaf is not attached to where I am intending to but instead, another adjacent leaves have their height turned to 0. The question, to put it more clearly perhaps: Is there any straightforward procedure to just add a single leaf to any dendrogram, next to an existing leaf at the height 0, and if there is, what might that be? As of now, it seems that the $merge has to be modified correctly, but what is the exact strategy, if there is one (other than redoing the whole clustering by hand)? > Alternatively, you could use as.dendrogram( res ) as the point of > departure and manipulate the value. Possibly, yes, but I am even less well-equipped with editing that sort of a data type. Sincerely, Jopi Harri Musicologist University of Turku Finland ______________________________________________ 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.
