The MI Procedure

Examples: MI Procedure

The Fish data described in the STEPDISC procedure are measurements of 159 fish of seven species caught in Finland’s lake Laengelmavesi. For each fish, the length, height, and width are measured. Three different length measurements are recorded: from the nose of the fish to the beginning of its tail (Length1), from the nose to the notch of its tail (Length2), and from the nose to the end of its tail (Length3). See Chapter 85, The STEPDISC Procedure, for more information.

The Fish1 data set is constructed from the Fish data set and contains only one species of the fish and the three length measurements. Some values have been set to missing, and the resulting data set has a monotone missing pattern in the variables Length1, Length2, and Length3. The Fish1 data set is used in Example 56.2 with the propensity score method and in Example 56.3 with the regression method.

The Fish2 data set is also constructed from the Fish data set and contains two species of fish. Some values have been set to missing, and the resulting data set has a monotone missing pattern in the variables Length, Height, Width, and Species. The Fish2 data set is used in Example 56.4 with the logistic regression method and in Example 56.5 with the discriminant function method. Note that some values of the variable Species have also been altered in the data set.

The Fish3 data set is similar to the data set Fish2 except some additional values have been set to missing and the resulting data set has an arbitrary missing pattern. The Fish3 data set is used in Example 56.7 and in Example 56.8.

The Fitness1 data set created in the section Getting Started: MI Procedure is used in other examples.

The following statements create the Fish1 data set:

*-----------------------------Fish1 Data-----------------------------*
| The data set contains one species of the fish (Bream) and          |
| three measurements: Length1, Length2, Length3.                     |
| Some values have been set to missing, and the resulting data set   |
| has a monotone missing pattern in the variables                    |
| Length1, Length2, and Length3.                                     |
*--------------------------------------------------------------------*;
data Fish1;
   title 'Fish Measurement Data';
   input Length1 Length2 Length3 @@;
   datalines;
23.2 25.4 30.0    24.0 26.3 31.2    23.9 26.5 31.1
26.3 29.0 33.5    26.5 29.0   .     26.8 29.7 34.7
26.8   .    .     27.6 30.0 35.0    27.6 30.0 35.1
28.5 30.7 36.2    28.4 31.0 36.2    28.7   .    .
29.1 31.5   .     29.5 32.0 37.3    29.4 32.0 37.2
29.4 32.0 37.2    30.4 33.0 38.3    30.4 33.0 38.5
30.9 33.5 38.6    31.0 33.5 38.7    31.3 34.0 39.5
31.4 34.0 39.2    31.5 34.5   .     31.8 35.0 40.6
31.9 35.0 40.5    31.8 35.0 40.9    32.0 35.0 40.6
32.7 36.0 41.5    32.8 36.0 41.6    33.5 37.0 42.6
35.0 38.5 44.1    35.0 38.5 44.0    36.2 39.5 45.3
37.4 41.0 45.9    38.0 41.0 46.5
;

The Fish2 data set contains two of the seven species in the Fish data set. For each of the two species (Bream and Pike), the length from the nose of the fish to the end of its tail, the height, and the width of each fish are measured.

The following statements create the Fish2 data set:

*-----------------------------Fish2 Data-----------------------------*
| The data set contains two species of the fish (Bream and Pike)     |
| and three measurements: Length, Height, Width.                     |
| Some values have been set to missing, and the resulting data set   |
| has a monotone missing pattern in the variables                    |
| Length, Height, Width, and Species.                                |
*--------------------------------------------------------------------*;
data Fish2;
   title 'Fish Measurement Data';
   input Species $ Length Height Width @@;
   datalines;
Bream   30.0  11.520  4.020         .   31.2  12.480  4.306
Bream   31.1  12.378  4.696     Bream   33.5  12.730  4.456
    .   34.0  12.444   .        Bream   34.7  13.602  4.927
Bream   34.5  14.180  5.279     Bream   35.0  12.670  4.690
Bream   35.1  14.005  4.844     Bream   36.2  14.227  4.959
    .   36.2  14.263   .        Bream   36.2  14.371  4.815
Bream   36.4  13.759  4.368     Bream   37.3  13.913  5.073
Bream   37.2  14.954  5.171     Bream   37.2  15.438  5.580
Bream   38.3  14.860  5.285     Bream   38.5  14.938  5.198
    .   38.6  15.633  5.134     Bream   38.7  14.474  5.728
Bream   39.5  15.129  5.570         .   39.2  15.994   .   
Bream   39.7  15.523  5.280     Bream   40.6  15.469  6.131
    .   40.5    .      .        Bream   40.9  16.360  6.053
Bream   40.6  16.362  6.090     Bream   41.5  16.517  5.852
Bream   41.6  16.890  6.198     Bream   42.6  18.957  6.603
Bream   44.1  18.037  6.306     Bream   44.0  18.084  6.292
Bream   45.3  18.754  6.750     Bream   45.9  18.635  6.747
Bream   46.5  17.624  6.371 
Pike    34.8   5.568  3.376     Pike    37.8   5.708  4.158
Pike    38.8   5.936  4.384        .    39.8    .      .   
Pike    40.5   7.290  4.577     Pike    41.0   6.396  3.977
   .    45.5   7.280  4.323     Pike    45.5   6.825  4.459
Pike    45.8   7.786  5.130     Pike    48.0   6.960  4.896
Pike    48.7   7.792  4.870     Pike    51.2   7.680  5.376
Pike    55.1   8.926  6.171        .    59.7  10.686   .   
Pike    64.0   9.600  6.144     Pike    64.0   9.600  6.144
Pike    68.0  10.812  7.480
;

The following statements create the Fish3 data set:

*-----------------------------Fish3 Data-----------------------------*
| The data set contains two species of the fish (Bream and Pike)     |
| and three measurements: Length, Height, Width.                     |
| Some values have been set to missing, and the resulting data set   |
| has an arbitrary missing pattern.                                  |
*--------------------------------------------------------------------*;
data Fish3;
   title 'Fish Measurement Data';
   input Species $ Length Height Width @@;
   datalines;
Bream   30.0  11.520  4.020         .   31.2  12.480  4.306
Bream   31.1  12.378  4.696     Bream   33.5  12.730  4.456
    .     .   12.444   .        Bream   34.7  13.602  4.927
Bream   34.5  14.180  5.279         .   35.0    .     4.690
Bream   35.1  14.005  4.844     Bream   36.2  14.227  4.959
    .   36.2  14.263   .        Bream   36.2  14.371  4.815
Bream   36.4  13.759  4.368     Bream   37.3  13.913  5.073
Bream   37.2  14.954  5.171         .   37.2    .     5.580
Bream   38.3  14.860  5.285     Bream   38.5  14.938  5.198
    .   38.6  15.633  5.134     Bream   38.7  14.474  5.728
Bream   39.5  15.129  5.570         .   39.2  15.994   .   
Bream   39.7  15.523  5.280     Bream   40.6  15.469  6.131
    .   40.5    .      .        Bream   40.9  16.360  6.053
Bream   40.6  16.362  6.090     Bream   41.5  16.517  5.852
Bream   41.6  16.890  6.198     Bream   42.6  18.957  6.603
Bream     .   18.037   .        Bream     .   18.084  6.292
Bream   45.3  18.754  6.750     Bream   45.9  18.635  6.747
Bream   46.5  17.624  6.371 
Pike    34.8   5.568  3.376     Pike    37.8   5.708  4.158
Pike    38.8   5.936  4.384        .    39.8    .      .   
Pike    40.5   7.290  4.577     Pike    41.0   6.396  3.977
   .    45.5   7.280  4.323     Pike    45.5   6.825  4.459
Pike    45.8   7.786  5.130     Pike    48.0   6.960  4.896
Pike    48.7   7.792  4.870     Pike    51.2   7.680  5.376
Pike    55.1   8.926  6.171        .    59.7  10.686   .   
Pike    64.0   9.600  6.144     Pike    64.0   9.600  6.144
Pike      .   10.812  7.480
;