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我試圖用正態分佈來計算mysql中的一個值,其中的意思可以是零或其他。在MySQL中計算規範分佈
編輯發現這一點,但不知道怎麼改並不MYSQL
create Function CND(@X float)
returns float
as
begin
declare @L float
declare @K float
declare @a1 float
declare @a2 float
declare @a3 float
declare @a4 float
declare @a5 float
set @a1 = 0.31938153
set @a2 = -0.356563782
set @a3 = 1.781477937
set @a4 = -1.821255978
set @a5 = 1.330274429
set @L = Abs(@X)
set @K = 1/(1 + 0.2316419 * @L)
declare @CND1 float
set @CND1 = 1 - 1/Sqrt(2 * Pi()) * Exp(-power(@L,2)/2) * (@a1 * @K +
@a2 * power(@K,2) + @a3 * power(@K,3) + @a4 * power(@K,4) + @a5 *
power(@K,5))
If @X < 0
begin
set @CND1 = 1 - @CND1
End
return @CND1
End
恭喜!你試過什麼了? – CanSpice
這已經在這裏得到解答: http://stackoverflow.com/questions/2360180/how-to-generate-a-gaussian-distribution-using-mysql-user-defined-function – diagonalbatman