DescTools (version 0.99.8.1)

Untable: Recover Original Data From Contingency Table

Description

Recreates the data.frame out of a contingency table x.

Usage

Untable(x, dimnames = NULL, type = NULL, rownames = NULL, colnames = NULL)

Arguments

x

a numeric vector, a matrix or a table interpreted as frequencies which are to be inflated to the original list

dimnames

the dimension names of x to be used for expanding. Can be used to expand a weight vector to its original values. If set to NULL (default) the dimnames of x will be used.

type

defines the data type generated. This allows to directly define factors or ordered factors, but also numeric values. See examples.

rownames

A names vector for the rownames of the resulting data.frame. If set to NULL (default) the names will be defined according to the table's dimnames.

colnames

A names vector for the colnames of the resulting data.frame. If set to NULL (default) the names will be defined according to the table's dimnames.

Value

• a data.frame with the detailed data (even if x was a 1-dimensional table)

Details

For x being a vector this reduces to rep(..., n) with n as vector (which is not supported by rep).

See Also

expand.grid, rep, gl, xtabs

Examples

d.titanic <- Untable(Titanic)
str(d.titanic)

# ... not the same as:
data.frame(Titanic)


tab <- table(set1=sample(letters[1:5], size=40, replace=TRUE), 
             set2=sample(letters[11:15], size=40, replace=TRUE))
Untable(tab)


# return a numeric vector by setting type and coerce to a vector by [,]
Untable(c(6,2,2), dimnames=list(1:3), type="as.numeric")[,]


# how to produce the original list based on frequencies, given as a data.frame
d.freq <- data.frame(xtabs(Freq ~ Sex + Survived, data=Titanic))

# a data list with each individual
d.data <- Untable( xtabs(c(1364, 126, 367, 344) ~ ., 
             expand.grid(levels(d.freq$Sex),levels(d.freq$Survived)))) 
head(d.data)

# expand a weights vector
Untable(c(1,4,5), dimnames=list(c("Zurich","Berlin","London")))

# and the same with a numeric vector 
Untable(c(1,4,5), dimnames=list(c(5,10,15)), type="as.numeric")[,]
# ... which again is nothing else than
rep(times=c(1,4,5), x=c(5,10,15))