I would like to define a wrapper to an inner function.
The idea is to repeat random sampling that uses one of r* base function (eg runif, rnorm, etc.) and let the user easily change this inner function and define custom ones.
The example below show a reproducible example that I cannot make work with tidyeval patterns and, more precisely, within a purrr::map. The evaluation of ... seems to not happen properly. I missed something on quosures evaluation but I cannot figure what. I also show below a workaround that works fine with a goold old replicate.
I would like to implement such behaviour in more complex cases and, more generally, be delighted for any pointer and to understand why the following does not work.
# use the tidyverse and define a dummy tibble
library(tidyverse)
df <- tibble(col1=seq(10, 50, 10), col2=col1+5)
# first random function, on top of stats::runif
random_1 <- function(x, min, max){
x %>%
rowwise() %>%
mutate(new=runif(1, min={{min}}, max={{max}})) %>%
ungroup()
}
# second random function, on top of stats::rnorm
random_2 <- function(x, mean, sd){
x %>%
rowwise() %>%
mutate(new=rnorm(1, mean={{mean}}, sd={{sd}})) %>%
ungroup()
}
# at top level, everything works fine
> df %>% random_1(min=col1, max=col2)
> df %>% random_2(mean=col1, sd=col2)
# So far so good
# we we wrap it for a single shot
random_fun <- function(x, random_fun, ...){
random_fun(x, ...)
}
random_fun(df, random_1, min=col1, max=col2)
# Still fine.
# Here comes the trouble:
random_fun_k <- function(df, k, random_fun, ...){
map(1:k, ~random_fun(df, ...))
}
random_fun_k(df, k=2, random_1, min=col1, max=col2)
Error in is_quosure(x) : argument "x" is missing, with no default
The following workaround around replicate works fine yet I would like to stick to tidyeval spirit:
random_fun_k_oldie <- function(df, k, random_fun, ...){
f <- random_fun(df, ...)
replicate(k, f, simplify=FALSE)
}
random_fun_k_oldie(df, k=2, random_1, min=col1, max=col2)
random_fun_k_oldie(df, k=2, random_2, mean=col1, sd=col2)
It may be better to use original lambda function i.e. function(x)
library(purrr)
random_fun_k <- function(df, k, random_fun, ...){
map(seq_len(k), function(x) random_fun(df, ...))
}
-testing
> random_fun_k(df, k=2, random_1, min=col1, max=col2)
[[1]]
# A tibble: 5 × 3
col1 col2 new
<dbl> <dbl> <dbl>
1 10 15 12.6
2 20 25 21.4
3 30 35 34.1
4 40 45 40.7
5 50 55 53.8
[[2]]
# A tibble: 5 × 3
col1 col2 new
<dbl> <dbl> <dbl>
1 10 15 13.1
2 20 25 24.2
3 30 35 33.8
4 40 45 41.6
5 50 55 50.9
NOTE: The function name and argument name seems to be the same rand_fun and this could cause some confusion as well (though it is not the source of the error). It may be better to rename the function argument differently
random_fun <- function(x, rn_fun, ...){
rn_fun(x, ...)
}