Rank Transformations

Figure 32.16 shows the transformations that are available when you select Rank from the Family list. The rank transformation of a variable $Y$ is a new variable that contains the ranks of the corresponding values of $Y$.

Figure 32.16: Rank Transformations

Rank Transformations


There are actually four different rank functions, depending on the options you select on the second page of the wizard. (See Figure 32.17.) If you select Assign arbitrarily as the Rank of Ties option, then the SAS/IML RANK function is used to compute ranks. If you select Assign to average, then the SAS/IML RANKTIE function is used. This is summarized in Table 32.6.

Figure 32.17: Rank Transformations

Rank Transformations


Table 32.6: Description of Rank Transformations

     

Name of

 

Transformation

Order

Rank of Ties

New Variable

Equation

rank(Y)

Ascending

Arbitrary

Rank_Y

rank(Y)

 

Descending

Arbitrary

Rank_Y

rank(-Y)

 

Ascending

Average

Rank_Y

ranktie(Y)

 

Descending

Average

Rank_Y

ranktie(-Y)