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.

Example A.4: A TYPE=SSCP Data Set Produced by PROC REG

The following statements create a TYPE=SSCP data set from the SocEcon input data set created in Example A.1: A TYPE=CORR Data Set Produced by PROC CORR:

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

The data set is created by PROC REG and is displayed in Figure A.5.

Figure A.5: A TYPE=SSCP Data Set Produced by PROC REG

Five Socioeconomic Variables

OBS _TYPE_ _NAME_ Intercept Pop School Employ Services House
1 SSCP Intercept 12.0 74900 137.30 28000 1450 204000
2 SSCP Pop 74900.0 597670000 857640.00 220440000 10959000 1278700000
3 SSCP School 137.3 857640 1606.05 324130 18152 2442100
4 SSCP Employ 28000.0 220440000 324130.00 82280000 4191000 486600000
5 SSCP Services 1450.0 10959000 18152.00 4191000 320500 30910000
6 SSCP House 204000.0 1278700000 2442100.00 486600000 30910000 3914000000
7 N   12.0 12 12.00 12 12 12