Resamples x with replacement R times, applies FUN to each resample,
and returns the percentile interval of the resampled statistics together
with the observed value.
Usage
bootstrap_ci(x, FUN = stats::median, R = 2000, conf.level = 0.95, seed = NULL)Arguments
- x
A numeric vector.
- FUN
A function of one vector returning a single number. Defaults to
stats::median().- R
Integer. Number of bootstrap resamples. Defaults to 2000.
- conf.level
Confidence level. Defaults to 0.95.
- seed
Integer or NULL. When supplied, sets the random seed so the interval is reproducible.
Value
A named numeric vector: estimate, lower, upper, with
attributes resamples, valid_resamples and, when the interval is
withheld, reason. The bounds are NA when fewer than 90% of resamples
give a value, or when every resample gives the same value, since neither
leaves a sampling distribution to read. The bounds
are NA when x has fewer than 3 finite values.
Examples
bootstrap_ci(mtcars$mpg, seed = 42)
#> estimate lower upper
#> 19.20 16.85 21.40
#> attr(,"resamples")
#> [1] 2000
#> attr(,"valid_resamples")
#> [1] 2000
bootstrap_ci(mtcars$mpg, FUN = mean, conf.level = 0.90, seed = 42)
#> estimate lower upper
#> 20.09062 18.41875 21.80031
#> attr(,"resamples")
#> [1] 2000
#> attr(,"valid_resamples")
#> [1] 2000