Variable Transformations

Scaling and Translation Transformations

Figure 32.15 shows the transformations that are available when you select Scaling/Translation from the Family list. These transformations are used to center and scale a variable. Equations for these transformations are given in Table 32.5.

Figure 32.15: Scaling and Translation Transformations

Scaling and Translation Transformations


Table 32.5: Description of Scaling and Translation Transformations

 

Default

Name of

 

Transformation

Parameter

New Variable

Equation

center(Y)

 

Center_Y

$Y-\mbox{mean}(Y)$

stdize(Y)

 

Stdize_Y

See text.

reflect(Y;a)

$a=0$

Reflect_Y

$2a - Y$

a+b*Y

$a=0, b=1$

Linear_Y

$a+b Y$


The stdize(Y) transformation transforms the data to have zero mean and unit variance.

The reflect(Y) transformation reflects the data about the value $Y=a$.