CI for the Population Quantile Difference of two Samples

This function calculates bootstrap CIs for the population value of q-quantile(x) - q-quantile(y), by default using "bca" bootstrap. Resampling is done within sample.

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

Arguments

x

A numeric vector.

y

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. Currently, "bootstrap" is the only option.

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.

See also

ci_median_diff()

Examples

x <- 10:30
y <- 1:30
ci_quantile_diff(x, y, R = 999)  # Use larger R
#> 
#> 	Two-sided 95% bootstrap confidence interval for the population value of
#> 	50% quantile(x) - 50% quantile(y) based on 999 bootstrap replications
#> 	and the bca method
#> 
#> Sample estimate: 4.5 
#> Confidence interval:
#>      2.5%     97.5% 
#> -2.456763 11.000000 
#>