dfidx: Data frames with indexes

In dfidx: Indexed Data Frames

Data frames with indexes

Description

data frames for which observations are defined by two (potentialy nested) indexes and for which series have thefore a natural tabular representation

Usage

dfidx(
  data,
  idx = NULL,
  drop.index = TRUE,
  as.factor = NULL,
  pkg = NULL,
  fancy.row.names = FALSE,
  subset = NULL,
  idnames = NULL,
  shape = c("long", "wide"),
  choice = NULL,
  varying = NULL,
  sep = ".",
  opposite = NULL,
  levels = NULL,
  ranked = FALSE,
  ...
)

Arguments

data	a data frame
idx	an index
drop.index	if TRUE (the default), remove the index series from the data.frame as stand alone series
as.factor	should the indexes be coerced to factors ?
pkg	if set, the resulting dfidx object is of class c("dfidx_pkg", "dfidx") which enables to write specific classes
fancy.row.names	if TRUE, fancy row names are computed
subset	a logical which defines a subset of rows to return
idnames	the names of the indexes
shape	either wide or long
choice	the choice
varying, sep	relevant for data sets in wide format, these arguments are passed to reshape
opposite	return the opposite of the series
levels	the levels for the second index
ranked	a boolean for ranked data
...	further arguments

Details

Indexes are stored as a data.frame column in the resulting dfidx object

Value

an object of class "dfidx"

Author(s)

Yves Croissant

Examples

if (requireNamespace("AER")){
data("TravelMode", package = "AER")

# the first two columns contain the index

TM1 <- dfidx(TravelMode)

# explicitely indicate the two indexes using either a vector or a
# list of two characters

TM2 <- dfidx(TravelMode, idx = c("individual", "mode"))

TM3 <- dfidx(TravelMode, idx = list("individual", "mode"))

# rename one or both indexes

TM3b <- dfidx(TravelMode, idnames = c(NA, "trmode"))

# for balanced data (with observations ordered by the first, then
# by the second index

# use the name of the first index

TM4 <- dfidx(TravelMode, idx = "individual", idnames = c("individual", "mode"))

# or an integer equal to the cardinal of the first index

TM5 <- dfidx(TravelMode, idx = 210, idnames = c("individual", "mode"))

# Indicate the values of the second index using the levels argument

TM5b <- dfidx(TravelMode, idx = 210, idnames = c("individual", "mode"),
levels = c("air", "train", "bus", "car"))
}

# Nesting structure for one of the index
if (requireNamespace("mlogit")){
data("JapaneseFDI", package = "mlogit")
JapaneseFDI <- dplyr::select(JapaneseFDI, 1:8)
JP1b <- dfidx(JapaneseFDI, idx = list("firm", c("region", "country")),
idnames = c("japf", "iso80"))
}
# Data in wide format
if (requireNamespace("mlogit")){
data("Fishing", package = "mlogit")
Fi <- dfidx(Fishing, shape = "wide", varying = 2:9, idnames = c("chid", "alt"))
}

dfidx documentation built on June 28, 2022, 5:06 p.m.