1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
|
Variable Labels
This panel has three main sections:
Transformations, divided into two stages
Variable checkboxes, letting you specify variables to be
transformed
Variable labels, telling you the current transformation for
each variable
Transformations:
The first stage offers very simple adjustments to the data,
intended primarily to allow you to shift the variables into the
domain of the transformation function you're interested in applying.
The second stage includes:
Restore Variable: remove transformation (second stage only)
Box-Cox power transformations, ( (x^exponent) - 1) / exponent
Absolute value
Inverse : 1 / x_j
Base 10 logarithm
Scale to [0,1]
Standardize : (x_j - mean(x)) / sigma(x)
Discretize, 2 levels: x_j > median(x) = 1; x_j <= median(x) = 0
Normal score
The transformation selected will be applied to all selected variables.
Caution: If one of the selected variables is in a "variable
group," as defined upon initialization, but not all members of
that group are selected, then this action will reset the groups.
See the man page for a description of variable groups.
Other notes:
If you try to select a transformation that can't be applied to a
particular variable (If, for example, you try to take a square
root of a variable which has some negative values ...), nothing will
be changed and an error message will be printed.
It is possible to transform variables during rotation, grand tour, or
in any other mode or action.
The column labels can be supplied in a file named fname.col, where fname
or fname.dat is the name of the data file, one label per row.
|
