mapwalkdiff.R

library(tidyverse)

# This is the example I used to show pwalk iterating and printing out things
#perhaps this is a horrible example and I'm using it incorrectly?
# if you substitute pmap for pwalk, you get exactly the same output. 

# make a simple plotting function
plot_points <- function(t) ggplot(t, aes(mpg, wt)) + geom_point()

#function that prints cylinder info, ggplot, and table 
print_func <-
  function(info, plot, table) {
    print(paste0("This is for ", info, " cylinders.\n"))
    print(plot)
    print(table)
  }

mtc_plot_n_save <-
  mtcars %>%                 # motortrend car dataset
    group_by(cyl) %>%       # group by cylinder
    nest(.key = "data") %>% # nest by cylinder
    mutate(plot = map(data, plot_points)) %>% # we made a graph for each subset
    mutate(filepath = map_chr(cyl, ~ file.path(getwd(), paste0(.x, ".png")))) #make the save paths

# print all the info
pwalk(list(info = mtc_plot_n_save$cyl, plot = mtc_plot_n_save$plot, table = mtc_plot_n_save$data), print_func) 


# print it all with pmap
pmap(list(info = mtc_plot_n_save$cyl, plot = mtc_plot_n_save$plot, table = mtc_plot_n_save$data), print_func)