This example uses discriminant monotone methods to impute values of a CLASS variable from the observed observation values in a data set with a monotone missing pattern.
The following statements impute the continuous variables Height
and Width
with the regression method and the classification variable Species
with the discriminant function method:
proc mi data=Fish2 seed=7545417 nimpute=3 out=outex5; class Species; monotone discrim( Species= Length Width/ details); var Length Width Species; run;
The "Model Information" table in Output 63.5.1 describes the method and options used in the multiple imputation process.
The "Monotone Model Specification" table in Output 63.5.2 describes methods and imputed variables in the imputation model. The procedure uses the regression method to impute the variables
Height
and Width
, and uses the logistic regression method to impute the variable Species
in the model.
The "Missing Data Patterns" table in Output 63.5.3 lists distinct missing data patterns with corresponding frequencies and percentages. The table confirms a monotone missing pattern for these variables.
When you use the DETAILS option, the parameters estimated from the observed data and the parameters used in each imputation are displayed in Output 63.5.4.
The following statements list the first 10 observations of the data set Outex5
in Output 63.5.5. Note that all missing values of the variables Width
and Species
are imputed.
proc print data=outex5(obs=10); title 'First 10 Observations of the Imputed Data Set'; run;
Output 63.5.5: Imputed Data Set
First 10 Observations of the Imputed Data Set |
Obs | _Imputation_ | Species | Length | Width |
---|---|---|---|---|
1 | 1 | Parkki | 16.5 | 2.32650 |
2 | 1 | Parkki | 17.4 | 2.31420 |
3 | 1 | Perch | 19.8 | 3.03975 |
4 | 1 | Parkki | 21.3 | 2.91810 |
5 | 1 | Parkki | 22.4 | 3.29280 |
6 | 1 | Perch | 23.2 | 3.29440 |
7 | 1 | Parkki | 23.2 | 3.41040 |
8 | 1 | Parkki | 24.1 | 3.15710 |
9 | 1 | Perch | 25.8 | 3.66360 |
10 | 1 | Parkki | 28.0 | 4.14400 |