as.epitable {epitools}R Documentation

Create r x 2 contigency table (exposure levels vs. binary outcome)

Description

Create r x 2 contigency table for r exposure levels and 2 outcome levels

Usage

as.epitable(..., trow = FALSE, tcol = FALSE)

Arguments

... see details
trow "transpose" (reverse order of) rows of table
tcol "transpose" (reverse order of) columns of table

Details

Creates r x 2 table with r exposure levels and 2 outcome levels (No vs. Yes). Arguments can be either (1) four or more integers that be converted into r x 2 table (the number of integers must be even), (2) two categorical vectors (1st vector is exposure with r levels, 2nd vector is outcome with 2 levels), (3) r x 2 contingency table, or (4) single vector that be converted into r x 2 table (the number of integers must be even). The contingency table created by this function is usually used for additional analyses, for example, the epitab function.

Setting trow = TRUE will reverse the order of the rows, and setting tcol = TRUE will reverse the order of the columns.

Value

Returns r x 2 contingency table, usually for additional analyses.

Note

Visit http://www.epitools.net for the latest.

Author(s)

Tomas Aragon, aragon@berkeley.edu, http://www.medepi.net/aragon

References

none

See Also

See also table.margins, margin.table

Examples

## single vector
dat <- c(88, 20, 555, 347)
as.epitable(dat)

## 4 or more integers
as.epitable(1,2,3,4,5,6)

## single matrix
as.epitable(matrix(1:6, 3, 2))

## two categorical vectors
exposure <- factor(sample(c("Low", "Med", "High"), 100, rep=TRUE),
                   levels=c("Low", "Med", "High"))
outcome <- factor(sample(c("No", "Yes"), 100, rep=TRUE))
as.epitable(exposure, outcome)
as.epitable("Exposure Level"=exposure, "Disease"=outcome)

## reversing row and/or column order
zz <- as.epitable("Exposure Level"=exposure, "Disease"=outcome)
zz
as.epitable(zz, trow = TRUE)
as.epitable(zz, tcol = TRUE)
as.epitable(zz, trow = TRUE, tcol = TRUE)


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