[R] Analyzing dendograms??

[Johan Lindberg]

I have used heatmap to visualize my microarray data. I have a matrix of 
M-values. I do the following.

#The distance between the columns.
sampdist <- dist(t(matrix[,]), method="euclidean")
sclus <- hclust(sampdist, method="average")
#The distance between the rows.
genedist <- dist(matrix[,], method="euclidean")
gclus <- hclust(genedist, method="average")
heatmap(matrix[,],Rowv=as.dendrogram(gclus),Colv=as.dendrogram(sclus), col=rbg)

So far so good. But what if I want to look at a group of genes that appear 
to have the same expression pattern in the heatmap? How do I zoom in on a 
dendogram in a heatmap to look at which genes that are forming the 
interesting clusters? I would really appreciate if someone could give me a 
pointer.

Best regards.

/ Johan



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Johan Lindberg
Royal Institute of Technology
AlbaNova University Center
Stockholm Center for Physics, Astronomy and Biotechnology
Department of Molecular Biotechnology
106 91 Stockholm, Sweden

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