[P] _get_eqspec -- Parsing tool for generating scores
_get_eqspec c_eqlist c_stub c_k : matname
_get_eqspec uses c_local to create local macros in the command that calls
it. Therefore, choose your c_* arguments carefully.
_get_eqspec is a programming tool that helps identify the equation
elements from a coefficient vector.
Local macros reserved by caller
c_eqlist will contain the list of equation names.
c_stub is the stub for local macros that will contain the names of the
independent variables (x variables) for a given equation, and whether
a constant was suppressed from that equation.
For example, if x1 and x2 are independent variables in the second
equation, then c_stub2xvars will contain "x1 x2". If the constant
term was suppressed from this equation, then c_stub2nocons will
contain "nocons"; otherwise it would be empty.
c_k will contain the number of equations.
matname identifies a coefficient vector. The most common case is where
matname is a temporary copy of e(b).