Syntax

The following statements are available in PROC LATTICE.

• PROC LATTICE < options > ;

  • BY variables ;

  • VAR variables ;

Three specific numeric SAS variables, Group , Block , and Treatmnt , must be present in the data set to which PROC LATTICE is applied. A fourth numeric variable named Rep must be present when the design involves repetition of the entire basic plan. (See the Input Data Set section on page 2073 for more information.)

Every numeric variable other than Group , Block , Treatmnt , or Rep in the input SAS data set may be considered a response variable. A VAR statement tells PROC LATTICE that only the variables listed in the VAR statement are to be considered response variables. If the VAR statement is omitted, then all numeric variables, excluding Group , Block , Treatmnt , and Rep , are considered response variables. PROC LATTICE performs an analysis for each response variable.

PROC LATTICE Statement

• PROC LATTICE < options > ;

You can specify the following options in the PROC LATTICE statement.

DATA = SAS-data-set

• names the SAS data set to be used by PROC LATTICE. If you omit the DATA= option, the most recently created SAS data set is used.

COVARIANCE

COV

• calculates sums of products for every possible pair of response variables. A sum of products is given for each source of variation in the analysis of variance table. For each pair of response variables, the one appearing later in the data set (or in the VAR statement) is the covariable.

BY Statement

• BY variables ;

You can specify a BY statement with PROC LATTICE to obtain separate analyses on observations in groups defined by the BY variables. When a BY statement appears, the procedure expects the input data set to be sorted in order of the BY variables. The variables are one or more variables in the input data set.

If your input data set is not sorted in ascending order, use one of the following alternatives:

• Sort the data using the SORT procedure with a similar BY statement.

• Specify the BY statement option NOTSORTED or DESCENDING in the BY statement for the LATTICE procedure. The NOTSORTED option does not mean that the data are unsorted but rather that the data are arranged in groups (according to values of the BY variables) and that these groups are not necessarily in alphabetical or increasing numeric order.

• Create an index on the BY variables using the DATASETS procedure (in base SAS software).

For more information on the BY statement, refer to the discussion in SAS Language Reference: Concepts . For more information on the DATASETS procedure, refer to the discussion in the SAS Procedures Guide .

VAR Statement

• VAR variables ;

The VAR statement specifies the response variables. If you do not include a VAR statement, all numeric variables in the data set are considered response variables (except Group , Block , Treatmnt , and Rep ).