plm.data {plm} | R Documentation |
This function was once used to transform a data frame in a format suitable for using with the estimation functions of plm
.
New code should rather use the more versatile function pdata.frame
.
plm.data(x, indexes = NULL)
x |
a |
indexes |
a vector (of length one or two) indicating the (individual and time) indexes (see Details). |
This function is kept due to backward compatibility of old code.
New code should use the function pdata.frame
instead.
indexes
can be:
a character string which is the name of the individual index variable, in this case a new variable called “time” containing the time index is added,
an integer, the number of individuals in the case of balanced panel, in this case two new variables “time” and “id” containing the individual and the time indexes are added,
a vector of two character strings which contains the names of the individual and of the time indexes.
An object of class c("plm.dim", "data.frame")
.
Yves Croissant
# There are 595 individuals data("Wages", package = "plm") Wages <- plm.data(Wages, 595) # Gasoline contains two variables which are individual and time indexes # The pdata.frame is called gas data("Gasoline", package = "plm") Gasoline <- plm.data(Gasoline, c("country","year")) summary(Gasoline) # Hedonic is an unbalanced panel, townid is the individual index data("Hedonic", package = "plm") Hedonic <- plm.data(Hedonic, "townid")