PREDICT_RF_CLASSIFIER

Applies a random forest model on an input relation.

Applies a random forest model on an input relation. PREDICT_RF_CLASSIFIER returns a VARCHAR data type that specifies one of the following, as determined by how the type parameter is set:

  • The predicted class (based on popular votes)

  • Probability of a class for each input instance.

Syntax

PREDICT_RF_CLASSIFIER ( input-columns
        USING PARAMETERS model_name = 'model-name'
            [, type = 'prediction-type']
            [, class = 'user-input-class']
            [, match_by_pos = match-by-position] )

Arguments

input-columns
Comma-separated list of columns to use from the input relation, or asterisk (*) to select all columns.

Parameters

model_name

Name of the model (case-insensitive).

type
Type of prediction to return, one of the following:

  • response (default): The class with the highest probability among all possible classes.

  • probability: Valid only if the class parameter is set, returns the probability of the specified class.

class
Class to use when the type parameter is set to probability. If you omit this parameter, the function uses the predicted class—the one with the popular vote. Thus, the predict function returns the probability that the input instance belongs to its predicted class.
match_by_pos

Boolean value that specifies how input columns are matched to model features:

  • true: Match by the position of columns in the input columns list.

  • false (default): Match by name.

Examples

=> SELECT PREDICT_RF_CLASSIFIER (Sepal_Length, Sepal_Width, Petal_Length, Petal_Width
       USING PARAMETERS model_name='myRFModel') FROM iris;
PREDICT_RF_CLASSIFIER
-----------------------
setosa
setosa
setosa
...
versicolor
versicolor
versicolor
...
virginica
virginica
virginica
...
(150 rows)

This example shows how you can use the PREDICT_RF_CLASSIFIER function, using the match_by_pos parameter:

=> SELECT PREDICT_RF_CLASSIFIER (Sepal_Length, Sepal_Width, Petal_Length, Petal_Width
                                USING PARAMETERS model_name='myRFModel', match_by_pos='true') FROM iris;
PREDICT_RF_CLASSIFIER
-----------------------
setosa
setosa
setosa
...
versicolor
versicolor
versicolor
...
virginica
virginica
virginica
...
(150 rows)

See also