Re: Groups in ordination


Hi David

I’m not sure what you mean. An ordination (SSH in PATN) doesn’t produce groups, only one of the classification methods (hierarchical or non-hierarchical). You could also import a set of groups (called a-priori in PATN).

If groups have been defined, you can view them in various forms in the ordination display-

1. Group centroids can be displayed (with appropriate colour) by pressing ‘c’ on the keyboard

2. Group centoid colours can be applied to all objects by pressing ‘g’

3. Group centroids can be displayed if you click the left mouse button off an object (and inter-centroid diffierences displayed by dragging betwen two centroids)

The legend in the ordination display will display the object (row) label and its colour. If group centriods are displayed, only those will be listed in the legend.

Has a classification been run or imported? Are the object (row) labels being displayed correctly on clicking the objects in the ordination plot, or in the legend (which doesn’t display group labels).

In version 3.02 undefined groups are usually labelled as ‘-1’ (version 3.03 we are now using ‘0’). If you click the groups tab on the right hand side of the data table, are there meaningful group numbers displayed?