This method extracts the model formulae
from fitted objects returned by systemfit.
Usage
## S3 method for class 'systemfit'
formula( x, ... )
## S3 method for class 'systemfit.equation'
formula( x, ... )
Arguments
x
an object of class systemfit.
...
currently not used.
Value
formula.systemfit.equation returns the formula
of a single equation of a systemfit object.
formula.systemfit.equation returns a list of formulae:
one formula object for each equation
of the systemfit object.
data( "Kmenta" )
eqDemand <- consump ~ price + income
eqSupply <- consump ~ price + farmPrice + trend
system <- list( demand = eqDemand, supply = eqSupply )
## perform a SUR estimation
fitsur <- systemfit( system, "SUR", data = Kmenta )
## formula of the second equation
formula( fitsur$eq[[2]] )
## all formulae of the system
formula( fitsur )