dcast.data.table
Faster utility function for converting wide-format data.frame
into a long format.
Internally uses data.table package functions melt.data.table
and dcast.data.table
.
DF.to.longDT(df_wide, return_DF = TRUE)
A data.frame
in long format
A data.frame
or data.table
in wide format
TRUE
(default) to return a data.frame
, FALSE
returns a data.table
Keeps all covariates that appear only once and at the first time-point constant (carry-forward).
All covariates that appear fewer than range(t) times are imputed with NA for missing time-points.
Observations with all NA's for all time-varying covariates are removed.
When removing NA's the time-varying covariates that are attributes (attnames) are not considered.
Other data manipulation functions:
DF.to.long()
,
doLTCF()