XLeratorDB/statistics Documentation
Updated: 9 August 2010
Use FACTLN to calculate the natural logarithm of a factorial. It can be useful to have the natural logarithm available because the limits of the float data type in SQL Server limit the maximum value of a factorial to 171! The natural logarithm can be substituted in many calculations; just remember to use the EXP() function on the final result.
Syntax
SELECT [wctStatistics].[wct].[FACTLN] (
<@Number, float,>)
Arguments
@Number
is the value to be evaluated by the function. @Number is an expression of type float or of a type that can be implicitly converted to float.
Return Types
float
Remarks
· If @Number < 0, FACTLN returns an error.
· @Number is truncated to zero decimal places.
Examples
SELECT wct.FACTLN(5)
This produces the following result
----------------------
4.78749174278205
(1 row(s) affected)
SELECT EXP(wct.FACTLN(200) - wct.FACTLN(175))
This produces the following result
----------------------
7.01372425899837E+56
(1 row(s) affected)