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.
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.