CI for a Population Quantile

Source: R/ci_measures_of_location.R

This function calculates CIs for a population quantile. By default, distribution-free CIs based on the binomial distribution are calculated, see Hahn and Meeker. Alternatively, bootstrap CIs are available (default "bca").

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

Arguments

x

A numeric vector.

q

A single probability value determining the quantile (0.5 for median).

probs

Lower and upper probabilities, by default c(0.025, 0.975).

type

Type of CI. One of "binomial" (default), or "bootstrap".

boot_type

Type of bootstrap CI. Only used for type = "bootstrap".

R

The number of bootstrap resamples. Only used for type = "bootstrap".

seed

An integer random seed. Only used for type = "bootstrap".

...

Further arguments passed to boot::boot().

Value

An object of class "cint", see ci_mean() for details.

References

Hahn, G. and Meeker, W. (1991). Statistical Intervals. Wiley 1991.

See also

ci_median()

Examples

x <- 1:100
ci_quantile(x, q = 0.25)
#> 
#> 	Two-sided 95% binomial confidence interval for the population 25%
#> 	quantile
#> 
#> Sample estimate: 25.75 
#> Confidence interval:
#>  2.5% 97.5% 
#>    17    35 
#>