Correlation Value for Clustering

Use this feature to specify a correlation value between 0.7 and 1 to use to determine the minimum radius when Automated Radius K Means is selected as the K-Means Clustering Method .

The higher the correlation, the more clusters that are defined, and the more highly members of each cluster correlate with one another. Denoting the correlation that you specify as Rho , the radius for SAS PROC FASTCLUS is set equal to sqrt(2 (Mean_USS)(1 - rho )) , where Mean_USS is the average of the columnwise uncorrected sums of squares.

Note : This option is available only when the Use K-Means clustering to reduce number of markers check box is checked.

To Specify a Correlation Radius:

Check the Use K-Means clustering to reduce number of markers check box.

Select Automated Radius K Means as the K-Means Clustering Method .

Either enter the desired value into the text field, or move the slider to the right or to the left to change the value.

Tip : To change the scale of the slider, right-click on the slider and select Rescale Slider from the pop-up menu. Change the upper and/or lower boundaries in the window that appears, to rescale the slider and click OK .