[R] Manually modifying an hclust dendrogram to remove singletons

[Mark Payne]

Hi,

Thanks for the replies - they have helped shaped my thinking and are
starting to push me in a better direction. Maybe I should explain a
little more about what I'm trying to achieve.

I am analysing satellite data across the global ocean, and am
interested in trying to classify areas of the ocean according to the
similarity between the pixels. Singletons in this case therefore
represent individual pixels that are different to the rest in terms of
the similarity metric, but aren't really all that interesting in terms
of the broad picture - I consider them "outliers" or "noise". However,
they are annoying when it comes to splitting up the dendrogram,
because I'm mainly interested in the reclassification of large areas
of ocean at each step, rather than changes in the similarity.

The dynamic tree-cut approach looks like a promising and sensible
solution to the problem - I'll see if I can get something out of it.

However,  this discussion has started me wondering how I can use the
spatial proximity of the pixels in the analysis - does anyone have any
insights? Can the WGCNA approach be used in such a context?

Best wishes,

Mark Payne