CRITERIA Subcommand (KNN command)
The CRITERIA
subcommand specifies
computational and resource settings for the KNN
procedure.
NUMFEATURES Keyword
The NUMFEATURES
keyword specifies
how automatic feature selection should select the number of features.
This keyword is ignored if /MODEL FEATURES=AUTO
is not in effect.
AUTO. Select a fixed number of features, where the number of features is computed from a formula. The number of features the procedure selects is equal to min(20,P) - J Forced, where P is the total number of features and J Forced is the number of forced features. This is the default.
FIXED (integer). Select a fixed
number of features, where the number of features is specified in advance. Specify a positive integer. It must be less than or equal to the
number of unique predictors available for feature selection. This
will be the number of predictors specified on the KNN
command, minus any specified on the EXCEPT
subcommand, minus any forced into
the model.
ERRORRATIO (MINCHANGE=value). Select features until the absolute change in the error ratio compared to the previous step is less than the criterion value. Specify a number greater than 0. The default value is 0.01.
PREDICTED Keyword
The PREDICTED
keyword specifies
the function used to compute the predicted value of scale response
variables.
This keyword is ignored if no dependent variable is specified.
MEAN. Compute predicted values based upon the mean value of the nearest neighbors. This is the default.
MEDIAN. Compute predicted values based upon the median value of the nearest neighbors.
WEIGHTFEATURES Keyword
The WEIGHTFEATURES
keyword
specifies whether to weight features by their normalized importance
when computing distances.
NO. Do not weight features by normalized importance. This is the default.
YES. Weight features
by normalized importance. Feature importance for a predictor
is calculated by the ratio of the error rate or sum-of-squares error
of the model with the predictor removed from the model to the error
rate or sum-of-squares error for the full model. Normalized importance
is calculated by reweighting the feature importance values so that
they sum to 1. The specification WEIGHTFEATURES=YES
is ignored with a warning if no dependent variable is specified.