POISSONINV
Updated: 31 July 2010
Use POISSONINV to calculate the inverse of the cumulative distribution function of the Poisson distribution.
The formula for the cumulative distribution function is:
Syntax
SELECT [wctStatistics].[wct].[POISSONINV] (
<@P, float,>
,<@Mean, float,>)
Arguments
@P
the cumulative distribution function. @P is an expression of type float or of a type that implicitly converts to float.
@Mean
is the mean of the distribution. @Mean is an expression of type float or of a type that implicitly converts to float.
Return Types
float
Remarks
· @P must be greater than zero and less than one (0 < @P < 1).
· @Mean must be greater than or equal to zero (0 ≤ @Mean).
Examples
Calculate the cumulative distribution function:
SELECT wct.POISSON(2,5,'True')
This produces the following result
----------------------
0.124652019483081
(1 row(s) affected)
Calculate the inverse:
SELECT wct.POISSONINV(0.124652019483081, 5)
This produces the following result
----------------------
2
(1 row(s) affected)