vcdExtra: expand.dft – R documentation

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expand.dft

Expand a frequency table to case form

Description

Converts a frequency table, given either as a table object or a data frame in frequency form to a data frame representing individual observations in the table.

Usage

expand.dft(x, var.names = NULL, freq = "Freq", ...)

expand.table(x, var.names = NULL, freq = "Freq", ...)

Arguments

`x`	A table object, or a data frame in frequency form containing factors and one numeric variable representing the cell frequency for that combination of factors.
`var.names`	A list of variable names for the factors, if you wish to override those already in the table
`freq`	The name of the frequency variable in the table
`...`	Other arguments passed down to `type.convert`. In particular, pay attention to `na.strings` (default: `na.strings=NA` if there are missing cells) and `as.is` (default: `as.is=FALSE`, converting character vectors to factors).

Details

expand.table is a synonym for expand.dft.

Value

A data frame containing the factors in the table and as many observations as are represented by the total of the freq variable.

Author(s)

Mark Schwarz

References

Originally posted on R-Help, Jan 20, 2009, http://tolstoy.newcastle.edu.au/R/e6/help/09/01/1873.html

Friendly, M. and Meyer, D. (2016). Discrete Data Analysis with R: Visualization and Modeling Techniques for Categorical and Count Data. Boca Raton, FL: Chapman & Hall/CRC. http://ddar.datavis.ca.

Examples

library(vcd)
art <- xtabs(~Treatment + Improved, data = Arthritis)
art
artdf <- expand.dft(art)
str(artdf)

# 1D case
(tab <- table(sample(head(letters), 20, replace=TRUE)))
expand.table(tab, var.names="letter")

vcdExtra

'vcd' Extensions and Additions

v0.7-5

GPL (>= 2)

Authors

Michael Friendly [aut, cre], Heather Turner [ctb], Achim Zeileis [ctb], Duncan Murdoch [ctb], David Firth [ctb]

Initial release

2021-01-22