Summarise the distribution of random draws
in an rvec, using credible intervals.
Usage
draws_ci(x, width = 0.95, prefix = NULL, na_rm = FALSE)
# S3 method for class 'rvec'
draws_ci(x, width = 0.95, prefix = NULL, na_rm = FALSE)
# S3 method for class 'rvec_chr'
draws_ci(x, width = 0.95, prefix = NULL, na_rm = FALSE)Arguments
- x
An object of class rvec.
- width
Width(s) of credible interval(s). One or more numbers greater than 0 and less than or equal to 1. Default is
0.975.- prefix
String to be added to the names of columns in the result. Defaults to name of
x.- na_rm
Whether to remove NAs before calculating summaries. Default is
FALSE.
Value
A tibble with three columns.
Warning
It is tempting to assign the results
of a call to draws_ci() to a
column in a data frame,
as in
my_df$ci <- draws_ci(my_rvec)
However, creating columns in this way can corrupt an ordinary data frames. For safer options, see the examples below.
See also
draws_quantile() gives more options
for forming quantiles.
Other ways of applying pre-specified functions across draws are:
Apply arbitrary function across draws:
For additional functions for summarising random draws, see
tidybayes
and ggdist.
Function as_list_col() converts rvecs into a
format that tidybayes and ggdist can work with.
Examples
set.seed(0)
m <- rbind(a = rnorm(100, mean = 5, sd = 2),
b = rnorm(100, mean = -3, sd = 3),
c = rnorm(100, mean = 0, sd = 20))
x <- rvec(m)
x
#> <rvec_dbl<100>[3]>
#> a b c
#> 4.9 (2, 8.2) -3.6 (-7.1, 2.9) 1.1 (-35, 36)
draws_ci(x)
#> # A tibble: 3 × 3
#> x.lower x.mid x.upper
#> <dbl> <dbl> <dbl>
#> 1 2.02 4.93 8.23
#> 2 -7.06 -3.61 2.87
#> 3 -35.3 1.06 36.1
draws_ci(x, width = c(0.5, 0.99))
#> # A tibble: 3 × 5
#> x.lower x.lower1 x.mid x.upper1 x.upper
#> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 1.21 3.86 4.93 6.25 9.85
#> 2 -7.81 -5.60 -3.61 -1.24 4.55
#> 3 -48.1 -12.3 1.06 13.0 47.4
draws_ci(x, prefix = "results")
#> # A tibble: 3 × 3
#> results.lower results.mid results.upper
#> <dbl> <dbl> <dbl>
#> 1 2.02 4.93 8.23
#> 2 -7.06 -3.61 2.87
#> 3 -35.3 1.06 36.1
## results from 'draws_ci'
## assigned to a data frame
library(dplyr)
df <- data.frame(x)
## base R approach
cbind(df, draws_ci(x))
#> x x.lower x.mid x.upper
#> 1 4.9 (2, 8.2) 2.017346 4.934077 8.228987
#> 2 -3.6 (-7.1, 2.9) -7.058286 -3.611295 2.872534
#> 3 1.1 (-35, 36) -35.275211 1.061243 36.052985
## a tidyverse alternative:
## mutate with no '='
df |> mutate(draws_ci(x))
#> x x.lower x.mid x.upper
#> 1 4.9 (2, 8.2) 2.017346 4.934077 8.228987
#> 2 -3.6 (-7.1, 2.9) -7.058286 -3.611295 2.872534
#> 3 1.1 (-35, 36) -35.275211 1.061243 36.052985