Syntax: CALIS Procedure

The following statements are available in PROC CALIS:

PROC CALIS <options> ;

LINEQS model equations ;

STD variance pattern ;

COV covariance pattern ;

RAM model list ;

VARNAMES variables ;

FACTOR <options> ;

COSAN matrix model ;

MATRIX matrix elements ;

PARAMETERS parameters ;

STRUCTEQ variables ;

BOUNDS boundary constraints ;

LINCON linear constraints ;

NLINCON nonlinear constraints ;

NLOPTIONS optimization options ;

BY variables ;

VAR variables ;

PARTIAL variables ;

FREQ variable ;

WEIGHT variable ;

SAS programming statements ;

• If no INRAM= data set is specified, one of the four statements that define the input form of the analysis model, LINEQS, RAM, FACTOR, or COSAN, must be used.

• The MATRIX statement can be used multiple times for the same or different matrices along with a COSAN or FACTOR statement. If the MATRIX statement is used multiple times for the same matrix, later definitions override earlier ones.

• The STD and COV statements can be used only with the LINEQS model statement.

• You can formulate a generalized COSAN model by using a COSAN statement. MATRIX statements can be used to define the elements of a matrix used in the COSAN statement. The input notation resembles the COSAN program of McDonald and Fraser (McDonald 1978, 1980).

• The RAM statement uses a simple list input that is especially suitable for describing McArdle’s RAM analysis model (McArdle 1980; McArdle and McDonald 1984) for causal and path analysis problems.

• The LINEQS statement formulates the analysis model by means of a system of linear equations similar to Bentler’s (1989) EQS program notation. The STD and COV statements can be used to define the variances and covariances corresponding to elements of matrix in the LINEQS model.

• A FACTOR statement can be used to compute a first-order exploratory or confirmatory factor (or component) analysis. The analysis of a simple exploratory factor analysis model performed by PROC CALIS is not as efficient as one performed by the FACTOR procedure. The CALIS procedure is designed for more general structural problems, and it needs significantly more computation time for a simple unrestricted factor or component analysis than PROC FACTOR does.

• You can add SAS programming statements to impose linear or nonlinear constraints on the parameters if you specify the model by means of a COSAN, LINEQS, or RAM statement. The PARAMETERS statement defines additional parameters that are needed as independent variables in your program code and that belong to the set of parameters to be estimated. Variable names used in the program code should differ from the preceding statement names. The code should respect the syntax rules of SAS statements usually used in the DATA step. See the section SAS Programming Statements for more information.

• The BOUNDS statement can be used to specify simple lower and upper boundary constraints for the parameters.

• You can specify general linear equality and inequality constraints with the LINCON statement (or via an INEST= data set). The NLINCON statement can be used to specify general nonlinear equality and inequality constraints by referring to nonlinear functions defined by programming statements.

• The VAR, PARTIAL, WEIGHT, FREQ, and BY statements can be used in the same way as in other procedures, such as the FACTOR or PRINCOMP procedure. You can select a subset of the input variables to analyze with the VAR statement. The PARTIAL statement defines a set of input variables that are chosen as partial variables for the analysis of a matrix of partial correlations or covariances. The BY statement specifies groups in which separate covariance structure analyses are performed.

The following sections describe the PROC CALIS statement and then describe the other statements in alphabetical order.