PREDICT_XGB_CLASSIFIER_CLASSES

Applies an XGBoost classifier model on an input relation and returns the probabilities of classes:.

Applies an XGBoost classifier model on an input relation and returns the probabilities of classes:

VARCHAR predicted column contains the class label with the highest probability.
Multiple FLOAT columns, where the first probability column contains the probability for the class reported in the predicted column. Other columns contain the probability of each class specified in the classes parameter.
Key columns with the same value and data type as matching input columns specified in parameter key_columns.

All trees contribute to a predicted probability for each response class, and the highest probability class is chosen.

Syntax

PREDICT_XGB_CLASSIFIER_CLASSES ( predictor-columns)
        USING PARAMETERS model_name = 'model-name'
            [, key_columns = 'key-columns']
            [, exclude_columns = 'excluded-columns']
            [, classes = 'classes']
            [, match_by_pos = match-by-position]
            [, probability_normalization = 'prob-normalization' ] )
OVER( [window-partition-clause] )

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).

key_columns

Comma-separated list of predictor column names that identify the output rows. To exclude these and other predictor columns from being used for prediction, include them in the argument list for parameter exclude_columns.

exclude_columns

Comma-separated list of columns from predictor-columns to exclude from processing.

classes

Comma-separated list of class labels in the model. The probability of belonging to each given class is predicted by the classifier. Values are case sensitive.

match_by_pos

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

false (default): Match by name.
true: Match by the position of columns in the predictor columns list.

probability_normalization

The classifier's normalization method, either softmax (multi-class classifier) or logit (binary classifier). If unspecified, the default logit function is used for normalization.

Examples

After creating an XGBoost classifier model with XGB_CLASSIFIER, you can use PREDICT_XGB_CLASSIFIER_CLASSES to view the probability of each classification. In this example, the XGBoost classifier model "xgb_iris" is used to predict the probability that a given flower belongs to a species of iris:

=> SELECT PREDICT_XGB_CLASSIFIER_CLASSES(Sepal_Length, Sepal_Width, Petal_Length, Petal_Width
    USING PARAMETERS model_name='xgb_iris') OVER (PARTITION BEST) FROM iris1;
  predicted  |    probability
------------+-------------------
 setosa     |   0.9999650465368
 setosa     |   0.9999650465368
 setosa     |   0.9999650465368
 setosa     |   0.9999650465368
 setosa     | 0.999911552783011
 setosa     |   0.9999650465368
 setosa     |   0.9999650465368
 setosa     |   0.9999650465368
 setosa     |   0.9999650465368
 setosa     |   0.9999650465368
 setosa     |   0.9999650465368
 setosa     |   0.9999650465368
 versicolor |  0.99991871763563
 .
 .
 .
(90 rows)

You can also specify additional classes. In this example, PREDICT_XGB_CLASSIFIER_CLASSES makes the same prediction as the previous example, but also returns the probability that a flower belongs to the specified classes "virginica" and "versicolor":

=> SELECT PREDICT_XGB_CLASSIFIER_CLASSES(Sepal_Length, Sepal_Width, Petal_Length, Petal_Width
    USING PARAMETERS model_name='xgb_iris', classes='virginica,versicolor', probability_normalization='logit') OVER (PARTITION BEST) FROM iris1;
 predicted  |    probability    |      virginica       |      versicolor
------------+-------------------+----------------------+----------------------
 setosa     |   0.9999650465368 | 1.16160301545536e-05 | 2.33374330460065e-05
 setosa     |   0.9999650465368 | 1.16160301545536e-05 | 2.33374330460065e-05
 setosa     |   0.9999650465368 | 1.16160301545536e-05 | 2.33374330460065e-05
 .
 .
 .
 versicolor |  0.99991871763563 | 6.45697562080953e-05 |     0.99991871763563
 versicolor | 0.999967282051702 | 1.60052775404199e-05 |    0.999967282051702
 versicolor | 0.999648819964864 |  0.00028366342010669 |    0.999648819964864
 .
 .
 .
 virginica  | 0.999977039257386 |    0.999977039257386 | 1.13305901169304e-05
 virginica  | 0.999977085131063 |    0.999977085131063 | 1.12847163501674e-05
 virginica  | 0.999977039257386 |    0.999977039257386 | 1.13305901169304e-05
(90 rows)