TYPE=UCOV Data Sets ! 7611 TYPE=UCOV Data Sets A TYPE=UCOV data set is similar to a TYPE=COV data set, except that the covariances are uncor- rected for the mean. Also, the corresponding value of the _TYPE_ variable is 'UCOV' instead of 'COV'. A TYPE=UCOV data set can be used as input for every SAS/STAT procedure that uses a TYPE=COV data set, except for the CANDISC, DISCRIM, and STEPDISC procedures. TYPE=UCOV data sets can be created by the CALIS and PRINCOMP procedures. TYPE=WEIGHT Data Sets The CALIS procedure creates and accepts as input a TYPE=WEIGHT data set. This data set con- tains the weight matrix used in generalized, weighted, or diagonally weighted least squares estima- tion. See Chapter 25, "The CALIS Procedure," for details. Definitional Formulas This section contrasts corrected and uncorrected SSCP, COV, and CORR matrices by showing how these matrices can be computed. In the following formulas, assume that the data consist of two variables, X and Y , with n observations.