I know how purrr effectively replaces the {l,v,s,m}apply functionals, but I wonder about the `apply`

function itself. I can see how if we have a 2d array what is done by `apply`

when `MARGIN=2`

, could be done by `purrr::map_dbl`

or even `dplyr::summarize_all`

, and when `MARGIN=1`

, this could be done by `purrr:pmap`

.

```
library(purrr)
library(tibble)
library(dplyr)
set.seed(123)
n <- 5
Df <- tibble(x = rnorm(n), y = rnorm(n), z = rnorm(n))
apply(Df, 2, sum)
x y z
0.9678513 -0.2215949 1.5395087
map_dbl(Df, sum)
x y z
0.9678513 -0.2215949 1.5395087
summarise_all(Df, sum)
# A tibble: 1 x 3
x y z
<dbl> <dbl> <dbl>
1 0.968 -0.222 1.54
apply(Df, 1, sum)
[1] 2.3786711 0.5905525 0.6944185 -0.5056617 -0.8722154
pmap_dbl(Df, sum)
[1] 2.3786711 0.5905525 0.6944185 -0.5056617 -0.8722154
```

But is there a `purrr`

way to do the following for example?

```
> apply(Titanic, c(2, 3), sum)
Age
Sex Child Adult
Male 64 1667
Female 45 425
```