The ML.MIN_MAX_SCALER function

This document describes the ML.MIN_MAX_SCALER function, which lets you scale a numerical_expression to the range [0, 1] . Negative values are set to 0 , and values above 1 are set to 1 .

When used in the TRANSFORM clause , the range of [0,1] is automatically used in prediction, and predicted values outside that range are similarly capped.

You can use this function with models that support manual feature preprocessing . For more information, see the following documents:

Syntax

ML.MIN_MAX_SCALER(numerical_expression) OVER()

Arguments

ML.MIN_MAX_SCALER takes the following argument:

numerical_expression : the numerical expression to scale.

Output

ML.MIN_MAX_SCALER returns a FLOAT64 value that represents the scaled numerical expression.

Example

The following example scales a set of numerical expressions to values between 0 and 1 :

 SELECT 
  
 f 
 , 
  
 ML 
 . 
 MIN_MAX_SCALER 
 ( 
 f 
 ) 
  
 OVER 
 () 
  
 AS 
  
 output 
 FROM 
  
 UNNEST 
 ([ 
 1 
 , 
 2 
 , 
 3 
 , 
 4 
 , 
 5 
 ]) 
  
 AS 
  
 f 
 ;

The output looks similar to the following:

+---+--------+
| f | output |
+---+--------+
| 4 |   0.75 |
| 2 |   0.25 |
| 1 |    0.0 |
| 3 |    0.5 |
| 5 |    1.0 |
+---+--------+

What's next

For information about feature preprocessing, see Feature preprocessing overview .