- const struct variable *v; /* The variable associated with this coefficient.
- The calling function should supply the variable
- when it creates the design matrix. The estimation
- procedure ignores the struct variable *. It is here so
- the caller can match parameters with relevant
- variables.
- */
+ double std_err; /* Standard error of the estimate. */
+ struct varinfo *v_info; /* Information pertaining to the
+ variable(s) associated with this
+ coefficient. The calling function
+ should initialize this value with the
+ functions in coefficient.c. The
+ estimation procedure ignores this
+ member. It is here so the caller can
+ match parameters with relevant variables
+ and values. If the coefficient is
+ associated with an interaction, then
+ v_info contains information for multiple
+ variables.
+ */
+ int n_vars; /* Number of variables associated with this coefficient.
+ Coefficients corresponding to interaction terms will
+ have more than one variable.
+ */