Figure 32.11 shows the transformations that are available when you select from the list. Equations for these transformations are given in Table 32.1.
Figure 32.11: Common Transformations
Table 32.1: Description of Common Transformations
Default 
Name of 


Transformation 
Parameter 
New Variable 
Equation 
log(Y+a) 

Log_Y 

log10(Y+a) 

Log10_Y 

sqrt(Y+a) 

Sqrt_Y 

exp(Y) 
Exp_Y 


1 / Y 
Inv_Y 


Y * Y 
Squared_Y 

The logarithmic transformations are often used when the scale of the data range exceeds an order of magnitude. The square root transformation is often used when your data are counts. The inverse transformation is often used to transform waiting times.