Agglomerative cluster analysis
This grid gives the membership of each cluster arranged by rows. The first
column gives the cluster formation number this is the cycle during which the
cluster was formed. The second column, termed the group label gives an
identifier for the cluster based on the membership. The group label is smallest
number of the column numbers of samples included within the group. Thus if
samples in columns 23 and 45 are joined to form a cluster the group label will be
23 If at some later point these samples are joined with the sample in column 1
then the group label for this new cluster will be 1. From column 3 onwards the
members of each cluster are given.
To print this output use File | Print.
Dendrogram Cluster analysis
The dendrogram of the cluster relationships is shown by clicking on the
The dendrogram is drawn with green and blue nodes. These can be selected by
clicking on them with the mouse to obtain information about the clusters or
change the colour or organisation of the dendrogram as follows.
Sizing the dendrogram to either fit the screen or make the sample titles
. The left hand button in the lower panel is a toggle which changes
between Fit Screen and Fit Text. When Fit Screen is active the dendrogram is
displayed in a single window but for larger dendrograms the labels will overlap.
To see the labels clearly, select Fit Text and use the slider to move down the
Changing the size of the font used for the labels
. Click on the Font button and
select font type and size.
Identifying the cluster group
. Click on the Cluster Id button in the lower panel
and move the cursor, which will be in the form of a question mark, to the node of
interest and click. The cluster group identification number will be shown. The
members of this cluster group can be found by referring to the Cluster groups
window (see above).
Changing the colour of a group of clustered samples for display or
. Click on the Change colour button in the lower panel and move the
cursor which will be in the form of a pointing hand to the basal node of the branch
of interest and click. The colour of the selected branch will change. To select the
colour to be used click on change colour.
Reversing the order of samples in a branch of the dendrogram
. This option is
primarily intended for use with TWINSPAN dendrograms, but is still active for
cluster analysis although it may give poor results. Click on the Switch Pos button
and move the cursor, which will be in the form of circle with arrows, to the node of
interest and click.
15.10 Cluster summary
This window presents a table of the sequence of cluster formation. The first
column, entitled Cluster, gives a sequential number to each cluster formed. The
group 1 and group 2 columns identify the groups which are united to form the
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