vcdExtra (version 0.7-1)

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).

Value

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

Details

expand.table is a synonym for expand.dft.

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.

See Also

type.convert, expandCategorical

Examples

# NOT RUN {
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")

# }