Chapter Contents |
Previous |
Next |
The MODEL Procedure |
The optional "name" is a string used to identify the restriction in the printed output and in the OUTEST= data set. The operator can be =, <, >, <= , or >=. The operator and second expression are optional, as in the TEST statement (=0).
Restriction expressions can be composed of parameter names, arithmetic operators, functions, and constants. Comparison operators (such as "=" or "<") and logical operators (such as "&") cannot be used in RESTRICT statement expressions. Parameters named in restriction expressions must be among the parameters estimated by the associated FIT statement. Expressions can refer to variables defined in the program.
The restriction expressions can be linear or nonlinear functions of the parameters.
The following is an example of the use of the RESTRICT statement:
proc model data=one; endogenous y1 y2; exogenous x1 x2; parms a b c; restrict b*(b+c) <= a; eq.one = -y1/c + a/x2 + b * x1**2 + c * x2**2; eq.two = -y2 * y1 + b * x2**2 - c/(2 * x1); fit one two / fiml; run;
Chapter Contents |
Previous |
Next |
Top |
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.