• Language: en

Source code for django.contrib.postgres.aggregates.statistics

from django.db.models import FloatField, IntegerField
from django.db.models.aggregates import Aggregate

__all__ = [
    'CovarPop', 'Corr', 'RegrAvgX', 'RegrAvgY', 'RegrCount', 'RegrIntercept',
    'RegrR2', 'RegrSlope', 'RegrSXX', 'RegrSXY', 'RegrSYY', 'StatAggregate',
]


class StatAggregate(Aggregate):
    output_field = FloatField()

    def __init__(self, y, x, output_field=None, filter=None):
        if not x or not y:
            raise ValueError('Both y and x must be provided.')
        super().__init__(y, x, output_field=output_field, filter=filter)

    def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
        return super().resolve_expression(query, allow_joins, reuse, summarize)


[docs]class Corr(StatAggregate): function = 'CORR'
[docs]class CovarPop(StatAggregate): def __init__(self, y, x, sample=False, filter=None): self.function = 'COVAR_SAMP' if sample else 'COVAR_POP' super().__init__(y, x, filter=filter)
[docs]class RegrAvgX(StatAggregate): function = 'REGR_AVGX'
[docs]class RegrAvgY(StatAggregate): function = 'REGR_AVGY'
[docs]class RegrCount(StatAggregate): function = 'REGR_COUNT' output_field = IntegerField() def convert_value(self, value, expression, connection): return 0 if value is None else value
[docs]class RegrIntercept(StatAggregate): function = 'REGR_INTERCEPT'
[docs]class RegrR2(StatAggregate): function = 'REGR_R2'
[docs]class RegrSlope(StatAggregate): function = 'REGR_SLOPE'
[docs]class RegrSXX(StatAggregate): function = 'REGR_SXX'
[docs]class RegrSXY(StatAggregate): function = 'REGR_SXY'
[docs]class RegrSYY(StatAggregate): function = 'REGR_SYY'
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