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Re: Appearance of DendrogramPlot

• To: mathgroup at smc.vnet.net
• Subject: [mg87523] Re: [mg87458] Appearance of DendrogramPlot
• From: Darren Glosemeyer <darreng at wolfram.com>
• Date: Sat, 12 Apr 2008 06:58:20 -0400 (EDT)
• References: <200804110542.BAA04662@smc.vnet.net>

W_Craig Carter wrote:
> I am finding that the leaves of my DendrogramPlot are too short:
>
> Example:
> Needs["HierarchicalClustering`"]
>
> DendrogramPlot[{1, 2, 10, 4, 8, -100, -101, -102},
>  LeafLabels -> (# &), Orientation -> Left]
>
> I am getting the lowest level clusters are not being resolved graphically.
>
> Thanks, Craig
>
>   

The issue is that the lengths of the leaves represent the distances 
between points or clusters, and the distance between the two main 
clusters is much larger than the distances between the points within 
each of those clusters. One possible way to visualize this would be to 
obtain the clustering via Agglomerate:

cls = Agglomerate[{1, 2, 10, 4, 8, -100, -101, -102}];

visualize the full dendrogram

DendrogramPlot[cls, LeafLabels -> (# &), Orientation -> Left]

and then split the clustering into the two main clusters and visualize 
them separately to zoom in on the two main clusters.

clsplt = ClusterSplit[cls, 2];

DendrogramPlot[clsplt[[1]], LeafLabels -> (# &), Orientation -> Left]

DendrogramPlot[clsplt[[2]], LeafLabels -> (# &), Orientation -> Left]


Darren Glosemeyer
Wolfram Research

• References:
  • Appearance of DendrogramPlot
    • From: "W_Craig Carter" <ccarter@mit.edu>