NoElbowDetectedError

exception neurocaps.exceptions.NoElbowDetectedError

Bases: Exception

Elbow Method Failure Exception.

This exception occurs in CAP.get_caps() when cluster_selection_method is set to “elbow” but kneed’s KneeLocator fails to detect a point of maximum curvature in the elbow curve.

This error may occur due to:

• The range of tested cluster sizes (k) is too restrictive and should be expanded, as the elbow likely occurs at a larger cluster size.

• Multiple elbows existing; thus, the value of the sensitivity (S) parameter of KneeLocator should be increased to be more conservative.

• The data lacking a natural clustering structure (exceptionally rare for fMRI data).