DAAG: excessRisk – R documentation

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excessRisk

Create and analyze multiway frequency or weighted frequency table

Description

This function creates a multi-way table of counts for the response given a set of classifying factors. Output facilitates a check on how the factor specified as margin may, after accounting for other classifying factors, affect the response.

Usage

excessRisk(form = weight ~ seatbelt + airbag, response = "dead", margin = "airbag",
data = DAAG::nassCDS, decpl = 4, printResults = TRUE)

Arguments

`form`	`form` is a formula in which classifying factors appear on the right, with an optional weight variable on the left.
`response`	`response` is a binary variable or two-level factor such that the response of interest is the relative number in the two levels.
`margin`	`margin` is the factor whose effect on the response, after accounting for other classifying factors, is of interest
`data`	`data` is a data frame in which variables and factors may be found
`decpl`	`decpl` is the number of decimal places in proportions that appear in the output
`printResults`	if `TRUE`, a tabular summary is printed.

Details

The best way to understand what this function does may be to run it with the default parameters, and/or with examples that appear below.

Value

The function returns a data frame, with one row for each combination of levels of factors on the right of the formula, but excluding the factor specified as margin

	Count for level 2 of response \& level 1 of margin
	Total tount for level 1 of margin
	Count for level 2 of response \& level 2 of margin
	Total count for level 2 of margin
	Proportion; divide count for level 1 of margin by total
	Proportion; divide count for level 2 of margin by total
	Excess count for level 2 of response in row; relative to the assumption that, in that row, there is no association between `response` and `margin`. This is the observed response (for the default arguments, number of dead) for level 2 (airbag deployed), less the number that would have been expected if the proportion had been that for level 1. (Negative values favor airbags.)

Author(s)

John Maindonald

References

See help(nassCDS)

Examples

excessRisk()
excessRisk(weight ~ airbag+seatbelt+dvcat)
UCB <- as.data.frame.table(UCBAdmissions)
excessRisk(Freq~Gender, response="Admit", margin="Gender",data=UCB)
excessRisk(Freq~Gender+Dept, response="Admit", margin="Gender",data=UCB)

DAAG

Data Analysis and Graphics Data and Functions

v1.24

GPL-3

Authors

John H. Maindonald and W. John Braun

Initial release