dynformula {plm} | R Documentation |
A function to create easily formula with lags
dynformula(formula, lag.form = NULL, diff.form = NULL, log.form = NULL)
formula |
a formula, |
lag.form |
a list containing the lag structure of each variable in the formula, |
diff.form |
a list of logical values indicating whether variables should be differenced, |
log.form |
a list of logical values indicating whether variables should be in logarithms. |
lag.form
, diff.form
and log.form
should be lists of length equal to the total number
variables. Each element of these lists is :
c(1,4)
means lags 1,2,3 and 4) or
a scalar (3
means lags 0,1,2,3 except for the left–hand side
variable for which it is 1,2,3) for lag.form
.
diff.form
and log.form
.
an object of class c("dynformula","formula")
, which is a
formula with four additional attributes : var
, the names of the variables in
the formula, lag
, diff
and log
which store the
information about lags, differences and logs.
Yves Croissant
# all variables in log, x1, x2 and x3 laged twice, y laged once and x3 differenced dynformula(y ~ x1+x2+x3, lag.form = list(2,y=1), diff.form = list(x3=TRUE), log.form = TRUE)