Source code for django.contrib.postgres.aggregates.statistics
from django.db.models import Aggregate, FloatField, IntegerField
__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)
[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'