Input Data Set of Statistics

The TTEST Procedure

Input Data Set of Statistics

PROC TTEST accepts data containing either observation values or summary statistics. It assumes that the DATA= data set contains statistics if it contains a character variable with name _TYPE_ or _STAT_. The TTEST procedure expects this character variable to contain the names of statistics. If both _TYPE_ and _STAT_ variables exist and are of type character, PROC TTEST expects _TYPE_ to contain the names of statistics including `N', `MEAN', and `STD' for each BY group (or for each class within each BY group for two-sample t tests). If no `N', `MEAN', or `STD' statistics exist, an error message is printed.

FREQ, WEIGHT, and PAIRED statements cannot be used with input data sets of statistics. BY, CLASS, and VAR statements are the same regardless of data set type. For paired comparisons, see the _DIF_ values for the _TYPE_=T observations in output produced by the OUTSTATS= option in the PROC COMPARE statement (refer to the SAS Procedures Guide).

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