MedianCI: Confidence Interval for the Median

Description

Calculates the confidence interval for the median.

Usage

MedianCI(x, conf.level = 0.95, na.rm = FALSE, 
         method = c("exact", "boot"), R = 999)

Arguments

a (non-empty) numeric vector of data values.

conf.level

confidence level of the interval

na.rm

logical. Should missing values be removed? Defaults to FALSE.

method

defining the type of interval that should be calculated (one out of "exact", "boot"). Default is "exact". See Details.

The number of bootstrap replicates. Usually this will be a single positive integer. See boot.ci for details.

Value

a numeric vector with 3 elements:
medianmedian
lwr.cilower bound of the confidence interval
upr.ciupper bound of the confidence interval

Details

The exact method is the way SAS is said to calculate the confidence interval. This is implemented in SignTest and is extracted from there. The boot confidence interval type is calculated by means of boot.ci with default type "basic". Use sapply, resp.apply, to get the confidence intervals from a data.frame or from a matrix.

Examples

Run this code

MedianCI(d.pizza$price, na.rm=TRUE)
MedianCI(d.pizza$price, conf.level=0.99, na.rm=TRUE)

t(round(sapply(d.pizza[,c("delivery_min","temperature","price")], MedianCI, na.rm=TRUE), 3))

MedianCI(d.pizza$price, na.rm=TRUE, method="exact")
MedianCI(d.pizza$price, na.rm=TRUE, method="boot")

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