SQL Server RANDSNORMAL Function

Updated 2023-10-18 19:33:29.050000

Description

Use the table-valued function RANDSNORMAL to generate a sequence of random numbers from the standard normal distribution.

Syntax

SELECT * FROM [westclintech].[wct].[RANDSNORMAL](
   <@Rows, int,>)

Arguments

@Rows

the number of rows to generate. @Rows must be of the type int or of a type that implicitly converts to int.

Return Type

table

colName	colDatatype	colDesc
Seq	int	A monotonically increasing sequence number
X	float	The random variable

Remarks

If @Rows is less than 1 then no rows are returned.

Examples

In this example we create a sequence 1,000,000 truncated random numbers from the standard normal distribution and COUNT the results. Elementary statistics leads us to expect the results to be distributed approximately like this:

X	COUNT
-4	31
-3	1318
-2	21400
-1	135905
0	682689
1	135905
2	21400
3	1318
4	31

SELECT X,
       COUNT(*) as [COUNT]
FROM
(SELECT wct.TRUNC(x, 0) as x FROM wct.RANDSNORMAL(1000000) ) n
GROUP BY X
ORDER BY 1;

This produces the following result. Your results will be different.

X	COUNT
-4	32
-3	1340
-2	21481
-1	135744
0	682726
1	136048
2	21333
3	1278
4	18