expand.dft: Expand a data.frame

In abd: The Analysis of Biological Data

Description

This function expands a data.frame based on a column (col.exp). Useful for generating long tables from contingency tables.

Usage

  expand.dft(x, col.exp, na.strings = "NA", as.is = FALSE, dec = ".")

Arguments

x	a data.frame
col.exp	a character string of the column name or the column number to use for "expansion"
na.strings	passed to type.convert
as.is	passed to type.convert
dec	passed to type.convert

Value

DF	a data.frame of x in "long" format.

Author(s)

Modified for the abd package by Kevin Middleton from a function posted by Marc Schwartz to the r-help mailing list.

References

See https://stat.ethz.ch/pipermail/r-help/2009-January/185561.html for discussion of expand.dft().

See Also

table

Examples

data(Aspirin)
Aspirin

# Specifying col.exp as character
Aspirin.expanded <- expand.dft(Aspirin, "count")
str(Aspirin.expanded)
xtabs(~treatment + cancer, Aspirin.expanded)

# Specifying col.exp as numeric
Aspirin.expanded <- expand.dft(Aspirin, 3)
str(Aspirin.expanded)
xtabs(~treatment + cancer, Aspirin.expanded)

# Plot 2X2 Contingency tables
plot( ~ treatment + cancer, data = Aspirin.expanded)
plot(table(Aspirin.expanded), main = "")
mosaicplot(~treatment + cancer, Aspirin.expanded)

# much nicer looking plots using vcd
if(require(vcd)) {
  mosaic(~treatment + cancer, Aspirin.expanded)
}

abd documentation built on May 2, 2019, 4:46 p.m.