Special SAS Data Sets

A TYPE=SSCP data set contains an uncorrected sum of squares and crossproducts (SSCP) matrix. TYPE=SSCP data sets are produced by PROC REG when the OUTSSCP= option is specified in the PROC REG statement. You can also create a TYPE=SSCP data set by using PROC CORR with the SSCP option and specifying the data set option TYPE=SSCP in parentheses following the name of the OUTP= or OUT= data set. You can also create TYPE=SSCP data sets in a DATA step; in this case, TYPE=SSCP must be specified as a data set option.

The variables in a TYPE=SSCP data set include those found in a TYPE=CORR data set. In addition, there is a variable called Intercept that contains crossproducts for the intercept (sums of the variables). The SSCP matrix is stored in observations with _TYPE_=’SSCP’, including a row with _NAME_=’Intercept’. PROC REG also outputs an observation with _TYPE_=’N’. PROC CORR includes observations with _TYPE_=’MEAN’ and _TYPE_=’STD’ as well. TYPE=SSCP data sets are used by the same procedures that use TYPE=CORR data sets.

proc reg data=SocEcon outsscp=regsscp;
   model house=pop school employ services / noprint;
run; quit;

proc print data=regsscp;
run;