ci_quantile_diff {confintr} R Documentation

## Confidence Interval for the Population Quantile Difference of two Samples

### Description

This function calculates bootstrap confidence intervals for the population value of q quantile(x) - q quantile(y).

### Usage

ci_quantile_diff(
x,
y,
q = 0.5,
probs = c(0.025, 0.975),
type = "bootstrap",
boot_type = c("bca", "perc", "norm", "basic"),
R = 9999,
seed = NULL,
...
)


### Arguments

 x A numeric vector. y A numeric vector. q A single probability value determining the quantile. Set to 0.5 for the median (default). probs Error probabilites. The default c(0.025, 0.975) gives a symmetric 95% confidence interval. type Type of confidence interval. Currently, "bootstrap" is the only option. boot_type Type of bootstrap confidence interval ("bca", "perc", "norm", "basic"). R The number of bootstrap resamples. seed An integer random seed. ... Further arguments passed to boot::boot.

### Details

Bootstrap confidence intervals are calculated by the package "boot". The default bootstrap type is "bca" (bias-corrected & accelerated) as it enjoys the property of being second order accurate and is transformation respecting (see Efron, p. 188). The sampling is done within sample.

### Value

A list with class cint containing these components:

• parameter: The parameter in question.

• interval: The confidence interval for the parameter.

• estimate: The estimate for the parameter.

• probs: A vector of error probabilities.

• type: The type of the interval.

• info: An additional description text for the interval.

### References

1. Efron, B. and Tibshirani R. J. (1994). An Introduction to the Bootstrap. Chapman & Hall/CRC.

2. Canty, A and Ripley B. (2019). boot: Bootstrap R (S-Plus) Functions.

ci_median_diff.
x <- 10:30