CODEWITHSUNDEEP
rpurrr
bheavner
bheavner

Reputation: 549

Pipe tibble with a list of logical vectors to map2()

How could I pipe a data frame consisting of a list of logical vectors and a list of character vectors to purrr::map2() to subset the character vectors using the logical vectors?

My efforts work without pipes, but I'm not sure how to do it with pipes:

For example, using this data frame:

a_pair = tibble(mask = list(TRUE, c(FALSE, TRUE), TRUE, TRUE, 
                            c(FALSE, FALSE, FALSE, TRUE), TRUE, TRUE, TRUE, 
                            TRUE, c(FALSE, FALSE, FALSE, TRUE)),
                strings = list(".", c("0.29966", "0.31145"), "0.48243", 
                               "0.55122", 
                               c("0.10099", "0.10142", "0.49873", "0.56246"), 
                               "0.56246", "0.10127", "0.70687", "0.68338", 
                               c("0.03365", "0.16895", "0.68338", "0.82954")))

This works:

library(purrr)

map2(a_pair$mask, a_pair$strings, function(logical, string) subset(string, logical))

But this (as suggested in a related question) doesn't:

a_pair %>% map2(., names(.), ~{subset(.y, .x)})
Error in subset.default(.y, .x) : 'subset' must be logical

Do I need to do some sort of unlisting, or reference the logical vectors in a different way?

Upvotes: 1

Views: 315

Answers (1)

MrFlick
MrFlick

Reputation: 206243

You should use

library(dplyr)
a_pair %>% {map2(.$strings, .$mask, subset)}

Using {} helps to prevent the data being automatically passed as the first parameter.

Or if you include the magrittr library, you can do

library(magrittr)
a_pair %$% map2(strings, mask, subset)

Upvotes: 2

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