RAND Function

The RAND function generates a random real number between 0 and 1. This function uses no parameters. Generated values are of Decimal type and have fifteen digits of precision after the decimal point. If you want to see all digits in the generated value, you might need to apply a different number format. See NUMFORMAT Function.

Basic Usage

derive type:single value: RAND() as:'random'

Output: For each row, generate a random number between 0 and 1 in the new random function.

Syntax and Arguments

There are no arguments for this function.

Examples

Example - Random values

In the following example, the source is simply the source column, and the random column is generated by the RAND function:

derive type:single value:RAND() as:'random'

Example - Type check functions

The RAND function is typically used to introduce randomness of some kind in your data. In the following example, it is used to perform sampling within your wider dataset. 

You want to extract a random sample of 20% of your set of orders for further study:

Transform:

You can use the following transform to generate a random integer from one to 10:

derive type:single value:round(RAND() * 10) as:'random'

You can now use the following transform to keep only the rows that contain random values that are in the top 20%, where the value is 9 or 10:

keep row:(random > 8)

Results: