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,
  name,
  position,
  sort = TRUE,
  drop.unused.levels = TRUE,
  ...
)

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 (deprecated)
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
name	name of the idx column
position	position of the idx column
sort	should the data frame be sorted using the indexes ?
drop.unused.levels	if TRUE the unused levels of the second index are droped
...	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

# the first two columns contain the indexes
mn <- dfidx(munnell)

# explicitely indicate the two indexes using either a vector or a
# list of two characters
mn <- dfidx(munnell, idx = c("state", "year"))
mn <- dfidx(munnell, idx = list("state", "year"))

# rename one or both indexes
mn <- dfidx(munnell, idnames = c(NA, "period"))

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

# use the name of the first index
mn <- dfidx(munnell, idx = "state", idnames = c("state", "year"))

# or an integer equal to the cardinal of the first index
mn <- dfidx(munnell, idx = 48L, idnames = c("state", "year"))

# Indicate the values of the second index using the levels argument
mn <- dfidx(munnell, idx = 48L, idnames = c("state", "year"),
            levels = 1970:1986)

# Nesting structure for one of the index
mn <- dfidx(munnell, idx = c(region = "state", president = "year"))

# Data in wide format
mn <- dfidx(munnell_wide, idx = c(region = "state"),
            varying = 3:36, sep = "_", idnames = c(NA, "year"))

# Customize the name and the position of the `idx` column
dfidx(munnell, position = 3, name = "index")

dfidx documentation built on Aug. 8, 2025, 7:10 p.m.