Hmisc (version 5.1-0)

ecdfSteps: ecdfSteps

Description

Compute Coordinates of an Empirical Distribution Function

Usage

ecdfSteps(x, extend)

Value

a list with components x and y

Arguments

x

numeric vector, possibly with NAs that are ignored

extend

a 2-vector do extend the range of x (low, high). Set extend=FALSE to not extend x, or leave it missing to extend it 1/20th of the observed range on other side.

Author

Frank Harrell

Details

For a numeric vector uses the R built-in ecdf function to compute coordinates of the ECDF, with extension slightly below and above the range of x by default. This is useful for ggplot2 where the ECDF may need to be transformed. The returned object is suitable for creating stratified statistics using data.table and other methods.

See Also

stats::ecdf()

Examples

ecdfSteps(0:10)
if (FALSE) {
# Use data.table for obtaining ECDFs by country and region
w <- d[, ecdfSteps(z, extend=c(1,11)), by=.(country, region)]  # d is a DT
# Use ggplot2 to make one graph with multiple regions' ECDFs
# and use faceting for countries
ggplot(w, aes(x, y, color=region)) + geom_step() +
       facet_wrap(~ country)
}