pvarcheck {plm} | R Documentation |
This function checks for each variable of a panel if it has an individual and a time variation.
pvarcheck(id,time,data)
id |
a vector containing the individual index, |
time |
a vector containing the time index, |
data |
a data.frame . |
pvarcheck
is called by pdata.frame
and by plm
in
there are some missing values.
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, |
pdata.frame
and plm
.
library(Ecdat) data(Produc) pvarcheck(Produc$state,Produc$year,Produc)