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Creating a SOM Centroid Plot

 

Overview

A centroid plot from a SOM plot can be used to see the profiles of the values in the dataset that have been associated with a particular node.

 

Actions

1. Click on a SOM experiment in the Experiments navigator. The item is highlighted.

2. Select Centroid Plot from the Clustering menu, or right-click on the item and select Centroid Plot from the shortcut menu. A centroid plot of the SOM experiment is displayed.

 

Interpretation

The SOM centroid plot shows the characteristics of the clusters, i.e., the representative profile (the centroid) and the fitness of the cluster in terms of the standard deviation above and below the representative. This provides important abstract information about how the gene expression data relates to the clustering provided by the SOM. It also shows the corresponding node's reference vector, which allows comparison of the representative profile of the cluster with the node's reference vector to determine how well (on average) the points associated with that node actually match that node's characteristics.

 

Using the Plot

Selecting Items

Displaying an Expression Value

Shared Selection

 

Plot Functions

Lookup Gene

Annotate

Create Gene List from Selection or Cluster

Exporting a .PNG Image

 

Customizing the Plot

Configuring Plot Components

Resizing a Plot

 

Related Topics:

Overview of Self-Organizing Maps (SOMs)

Tutorial 4: Self-Organizing Maps