This is related to the questions 1 and 2
I have a list of objects (in my case they are also lists AFAII), as returned by running:
gof_stats <- models %>% map(gof_stats)
Where models is a list of models created by fitdistrplus and gof_stats is a function that computes goodness of fit stats for each model.
Now if I want to extract a specific stat from that list I could do something like:
gof_stats[[1]]$cvm
to get the Cramer von Mises stat. I can achieve the same over the whole list (as per the linked questions) like so:
cvms <- sapply(gof_stats, "[[", "cvm")
Is there a way to do the same using dplyr/purrr syntax?
BONUS: How would you handle the case where some of the elements in the models list are NULL?
If you prefer map to sapply for this, you can do
library(purrr)
map(gof_stats, ~ .x[["cvm"]])
If you just like pipes you could do
gof_stats %>% sapply("[[", "cvm")
Your question is about lists, not data frames, so dplyr doesn't really apply. You may want to look up ?magrittr::multiply_by to see a list of other aliases from the package that defines %>% as you seem to like piping. For example, magrittr::extract2 is an alias of [[ that can be easily used in the middle of a piping chain.
As for your bonus, I would pre-filter the list to remove NULL elements before attempting to extract things.