The value to indicate here depends greatly on the choice of variable . For example, if you choose RSQ (R-Squared) as your X -axis variable ( Variable to Define Tree Axis ), then a value here should be between 0 and 1 where a higher correlation results in more clusters defined. Alternatively, for the default HEIGHT Variable (Average Distance Between Clusters), a higher number defines fewer clusters. Both LENGTH and NCL must be integer values and be greater than 2 for meaningful results.Caution : Choosing a cutoff level that is unsuitable to the X -axis variable might cause errors.
Select Tree Axis Cutoff Level in Options to Define Cluster Membership to enable the Cutoff Level of Tree Axis field.