pdim {plm} | R Documentation |
This function checks the number of individuals and time observations in the panel and whether it is balanced or not.
pdim(x,...) ## S3 method for class 'pdata.frame': pdim(x,...) ## S3 method for class 'data.frame': pdim(x,id,time,...)
x |
a data.frame or a pdata.frame , |
id |
the individual index, |
time |
the time index, |
... |
further arguments. |
pdim
is called by pdata.frame
and by plm
if
there are some missing values.
an object of class plim
containing the following elements :
nT |
a list containing n , the number of individuals,
T , the number of time observations, N the total number
of observations, |
TinT |
a list containing two vectors : Ti gives the
number of observations for each individuals and nt gives
the number of individuals observed for each period, |
balanced |
a logical value : TRUE for a balanced panel,
FALSE for an unbalanced panel, |
panel.names |
a list of character vectors : id.names
contains the names of each individual and time.names
contains the names of each period. |
Yves Croissant
pdata.frame
and plm
library(Ecdat) data(Produc) pdim(Produc,"state","year")