The value in each cell is the number of positions in the
Note also that it is possible to specify that some proximities are missing, e.g. the proximity between Man and Donkey in the above example. Just enter any non-numeric values such as " Now it's fairly easy to see that Man and Monkey are closely related on this criterion, as are Horse and Donkey, and that Dog is fairly distinct from these two clusters. Clustering proximities "by inspection" is quite easy with 5 cases, or even with 10; but it's not so easy when you have 500 cases, or 5000 cases. That's where Clustan software becomes essential. Proximities can be either of type ClustanGraphics can read read proximities in four formats, illustrated below:
In all formats, the diagonal elements are disregarded; however, a value should be entered for each diagonal element when using Square Matrix format. The Upper Triangular and Lower Triangular formats treat the proximity matrix as symmetric. The Square Matrix format can be symmetric or asymmetric. If it is asymmetric, then ClustanGraphics will convert it to a symmetric matrix. There are 4 conversion options: Sum proximities p Average proximity p
Minimum proximity p Maximum proximity p Proximity List format can be symmetric or asymmetric. The first 2 values on each line are case numbers (in any order), and the third value is the proximity for that pair of cases. The list does not have to be exhaustive, as ClustanGraphics will assume that any omitted proximities correspond to maximum dissimilarity, or minimum similarity. This type of format is useful for large, sparse matrices - for example, telephone calling traffic where the traffic between nodes is heavily localised.
We have also discussed Network Analysis using Clustan software in another web page. |