InstantForum.NET v2.9.0SQLServerCentralhttp://www.sqlservercentral.com/Forums/notifications@sqlservercentral.comTue, 21 May 2013 13:02:48 GMT20http://www.sqlservercentral.com/Forums/Topic965963-338-1.aspxOut of the box there is no equivalent in SQL Server (up to 2012) for NORMDIST.NORMDIST computes the Normal Distribution PDF (Probability Density Function) when the cumulative parameter is false and the CDF (Cumulative Distribution Function) otherwise.The PDF can be computed from the definition and is pretty straight forward, the CDF however has no close form and can only be approximated.I've developed a function for the PDF and a set of functions using different approximations for the CDF.You can read my analysis in:http://formaldev.blogspot.com.au/2012/09/T-SQL-NORMDIST-1.htmland either copy paste the ones you want from the posts or get them from the project page for the blog posts at:https://tsqlnormdist.codeplex.com/Wed, 12 Sep 2012 20:15:23 GMTideahttp://www.sqlservercentral.com/Forums/Topic965963-338-1.aspxIf it helps anyone, this is how my function looks like. Thanks again to all who helped me. CREATE FUNCTION [dbo].[udf_NORMDIST](@value FLOAT, @mean FLOAT, @sigma FLOAT, @cummulative BIT)RETURNS NUMERIC(28,8)AS/****************************************************************************************NAME: udf_NORMDISTWRITTEN BY: Tim Pickering http://www.eggheadcafe.com/software/aspnet/31021839/normdistx-mean-standarddevtrue-in-sql-2005.aspxDATE: 2010/07/13 PURPOSE: Mimics Excel's Function NORMDIST Usage: SELECT dbo.udf_NORMDIST(.48321740,0,1,0) OUTPUT: 0.35498205REVISION HISTORYDate Developer Details2010/08/11 LC Posted Function*****************************************************************************************/BEGIN DECLARE @x FLOAT DECLARE @z FLOAT DECLARE @t FLOAT DECLARE @ans FLOAT DECLARE @returnvalue FLOAT SELECT @x = (@value-@mean)/@sigma IF (@cummulative = 1) BEGIN SELECT @z = abs(@x)/sqrt(2.0) SELECT @t = 1.0/(1.0+0.5*@z) SELECT @ans = @t*exp(-@z*@z-1.26551223+@t*(1.00002368+@t*(0.37409196+@t*(0.09678418+@t*(-0.18628806+@t*(0.27886807+@t*(-1.13520398+@t*(1.48851587+@t*(-0.82215223+@t*0.17087277)))))))))/2.0 IF (@x <= 0) SELECT @returnvalue = @ans ELSE SELECT @returnvalue = 1-@ans END ELSE BEGIN SELECT @returnvalue = exp(-@x*@x/2.0)/sqrt(2.0*3.14159265358979) ENDRETURN CAST(@returnvalue AS NUMERIC(28,8))ENDFri, 13 Aug 2010 06:31:25 GMTL Cernigliahttp://www.sqlservercentral.com/Forums/Topic965963-338-1.aspxNothing right out of the box that i know of. You will probably have to write your own. (or borrow somebody else's)Mon, 09 Aug 2010 09:01:58 GMTSean Langehttp://www.sqlservercentral.com/Forums/Topic965963-338-1.aspxIs there an equivalent of Excel's NORMDIST function in SQL Server 2005?Mon, 09 Aug 2010 07:55:35 GMTL Cerniglia