Sorry to jump in a long-dead thread, but this is clearly an important topic, as several SO questions addressing are highly "liked" e.g, in this SO question and also because hadley seems to be "questioning" the best approach in this GH issue
I've read through several threads and it seems it's prefered not to use
As solely an end-user, this approach is not nearly as intuitive as the
rowwise approach (to me at least) for a few reasons.
pmap help and examples are not very informative (lumped into purrr::map et al) (as pointed out below as well).
pmap_... doesn't quite work the same as other
map_ syntax (my attempts below)
- I don't understand why there can't be a
mutate_rowwise-type option, so the underlying data grouping is not altered?
I'm sure much of this is just my limited understanding of the internals, but I've managed to maneuver the
purrr framework much easier than
pmap for some reason.
mtcars %>% as_tibble() %>%
mutate(new_mean_var = mean(c(vs, am, gear, carb)),
new_mean_pmap = pmap_dbl(.l = list(vs, am, gear, carb), mean), # NO
new_mean_pmap_attempt2 = pmap_dbl(.l = list(vs, am, gear, carb), ~mean(c(vs, am, gear, carb))), # NO
new_mean_pmap_attempt3 = pmap_dbl(.l = list(vs, am, gear, carb), function(x,y,z, zz) mean(c(x,y,z, zz)))) # YES