DM 'CLEAR LOG';
DM 'CLEAR OUTPUT';
OPTIONS LINESIZE=72 NODATE NONUMBER;
TITLE1   'Merging data sets';
DATA file1;
     INFILE 'a:\mergdat1.txt';
     INPUT x plot sample;
PROC PRINT DATA = file1;
Title2  'mergdat1 data';
PROC SORT DATA=file1;
          BY plot sample;
DATA file2;
     INFILE 'a:\mergdat2.txt';
     INPUT y plot sample x;
PROC PRINT  DATA = file2;
Title2 'mergdat2 data';
PROC SORT DATA=file2;
          BY plot sample;
DATA file3;
     FILE 'a:\newfile.dat';
     MERGE file1 (RENAME=(x=x1)) file2 (RENAME=(x=x2));
     BY plot sample;
      MEANX=MEAN(x1,x2);
      STDX=STD(x1,x2);
      PUT plot sample x1 x2 meanx stdx y;
PROC PRINT DATA =file3;
TITLE2 'complete merged data';
RUN;