Hi everyone, I am doing simulations to test multiple imputation procedures implemented in PROC MI. For one of my datasets, I had the following error message : ERROR: The set of classification levels for centre, generated for the imputed variable y_4, does not include the level c3 for observations that have missing y_4 values. It occured when I was imputing with the MONOTONE REGRESSION technique (on a monotone dataset, of course). The code below (on SAS V9.4) reproduces such error: DATA myData;
INPUT centre $ y_1 y_2 y_3 y_4;
DATALINES;
c3 11 27 22 .
c3 10 14 21 .
c3 2 21 15 .
c3 1 10 12 .
c2 24 57 21 12
c2 3 21 14 7
c2 2 45 65 12
c2 1 2 3 4
c1 4 5 12 1
c1 12 32 54 12
c1 15 12 32 14
c1 14 21 10 12
;
RUN;
PROC MI DATA=myData OUT=imputed;
CLASS centre;
VAR centre y_1 y_2 y_3 y_4;
MONOTONE REG;
RUN; But with FCS REGRESSION, no problem ! PROC MI DATA=myData OUT=imputed;
CLASS centre;
VAR centre y_1 y_2 y_3 y_4;
FCS REG;
RUN; Yet, the SAS user guide for PROC MI (pdf version available here) seems to assert that for monotone datasets, FCS REGRESSION fill-in phase acts like a MONOTONE REGRESSION (page 5894 to 5895 and 5902 to 5903). How to explain that the error occurs only for MONOTONE REGRESSION ? Thanks in advance
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