Databases Reference
In-Depth Information
However, a cousin of January 31 in February will not exist because
February will not have a thirty-first day.
Figure A-4:
Cousin () function.
See also: ParallelPeriod (), PeriodsToDate ()
Covariance (
set
,
y numeric expression
[,
x numeric expression
])
Returns: number
Standard ( 9)
CovarianceN (
set
,
y numeric expression
[,
x numeric expression
])
Returns: number
Standard
Covariance () calculates the population covariance and uses the biased
population formula (dividing by the number of x-y pairs). CovarianceN ()
calculates the sample covariance and uses the unbiased population for-
mula (dividing by the number of x-y pairs minus 1). If either the
y
or the
x
numeric value expression
is a logical or text value, or if the value is
NULL, then that tuple and its related values are not included in the correl-
ation. Zero values for y and x are included.
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