R: Updates a femlm estimation

update.femlm

R Documentation

Updates a femlm estimation

Description

Updates and re-estimates a femlm model. This function updates the formulas and use previous starting values to estimate a new femlm model. The data is obtained from the original call.

Usage

## S3 method for class 'femlm'
update(object, fml.update, ...)

Arguments

`object`	An object of class `femlm`. Typically the result of a `femlm` estimation.
`fml.update`	Changes to be made to the original argument `fml`. See more information on `update.formula`. You can add/withdraw both variables and clusters. E.g. `. ~ . + x2 \| . + z2` would add the variable `x2` and the cluster `z2` to the former estimation.
`...`	Other arguments to be passed to the function `femlm`.

Value

It returns a femlm object (see details in femlm.

Author(s)

Laurent Berge

Examples


# Example using trade data
data(trade)

# main estimation
est_pois <- femlm(Euros ~ log(dist_km) | Origin + Destination, trade)

# we add the variable log(Year)
est_2 <- update(est_pois, . ~ . + log(Year))

# we add another cluster: "Product"
est_3 <- update(est_2, . ~ . | . + Product)

# we remove the cluster "Origin" and the variable log(dist_km)
est_4 <- update(est_3, . ~ . - log(dist_km) | . - Origin)

# Quick look at the 4 estimations
res2table(est_pois, est_2, est_3, est_4)