statsmodels.stats.outliers_influence.OLSInfluence.dffits#

OLSInfluence.dffits[source]#

dffits measure for influence of an observation

Returns:
dffitsfloat

The dffits measure for each observation, which is a measure of the influence of a single data point on the predicted value of a model.

dffits_thresholdfloat

The threshold to determine if the influence of an observation is large. The threshold is 2 * sqrt(k / n).

based on resid_studentized_external, uses results from
leave-one-observation-out loop.
It is recommended that observations with dffits large than a
threshold of 2 sqrt{k / n} where k is the number of parameters, should
be investigated.
Based on Wikipedia <https://en.wikipedia.org/wiki/DFFITS>_