plm (version 0.1-1)

pvarcheck: Check wheter variables of a panel exhibit individual and time variations

Description

This function checks for each variable of a panel if it has an individual and a time variation.

Usage

pvarcheck(id,time,data)

Arguments

id

a vector containing the individual index,

time

a vector containing the time index,

data

a data.frame.

Value

• a list containing the following elements :
• id.var
  a logical vector with values TRUE if the variable has individual variation, FALSE otherwise,
• time.var
  a logical vector with values TRUE if the variable has time variation, FALSE otherwise,

Details

pvarcheck is called by pdata.frame and by plm in there are some missing values.

See Also

pdata.frame and plm.

Examples

library(Ecdat)
data(Produc)
pvarcheck(Produc$state,Produc$year,Produc)