update to use repurrrsive for data

cwickham · cwickham · commit b2214be0ea8e · 2017-05-31T13:37:50.000-07:00
diff --git a/01-map.R b/01-map.R
@@ -1,25 +1,26 @@
 library(purrr)
 
-# loads objects: films, people, vehicles, starships, 
-# planets & species
-load("data/swapi.rda")
+library(repurrrsive)
+# includes objects: sw_films, sw_people, sw_vehicles, 
+# sw_starships, sw_planets & sw_species
 
-# How many elements are in people?
-length(people)
+# How many elements are in sw_people?
+length(sw_people)
 
-# Who is the first person in people?
-people[[1]]  # Luke!
+# Who is the first person in sw_people?
+sw_people[[1]]  # Luke!
 
 # A list inside a list
-people[1]
+sw_people[1]
 
 # A list, dropped one level of heirachy
-people[[1]]
+sw_people[[1]]
 
 # How many starships has each character been on?
-map(people, ~ length(.x$starships))
+map(sw_people, ~ length(.x$starships))
 
 # For later
-planet_lookup <- map_chr(planets, "name")  %>% set_names(map_chr(planets, "url"))
+planet_lookup <- map_chr(sw_planets, "name")  %>% 
+  set_names(map_chr(sw_planets, "url"))
 planet_lookup
 save(planet_lookup, file = "data/planet_lookup.rda", compress = FALSE)
diff --git a/02-typed-functions.R b/02-typed-functions.R
@@ -1,40 +1,44 @@
 library(purrr)
-load("data/swapi.rda")
+library(repurrrsive)
 
 # Typed functions
-people <- people %>% set_names(map_chr(people, "name"))
+sw_people <- sw_people %>% set_names(map_chr(sw_people, "name"))
 
 # How many starships has each character been in?
-map(people, ~ length(.x[["starships"]]))
+map(sw_people, ~ length(.x[["starships"]]))
 
 # What color is each characters hair?
-map(people, ~ .x[["hair_color"]])
+map(sw_people, ~ .x[["hair_color"]])
 
 # Is the character male?
-map(people, ~ .x[["gender"]] == "male")
+map(sw_people, ~ .x[["gender"]] == "male")
 
 # How heavy is each character?
-map(people, ~ .x[["mass"]])
+map(sw_people, ~ .x[["mass"]])
 
 
+
+
+# Solutions ---------------------------------------------------------------
+
 # How many starships has each character been in?
-map_int(people, ~ length(.x[["starships"]]))
+map_int(sw_people, ~ length(.x[["starships"]]))
 
 # What color is each characters hair?
-map_chr(people, ~ .x[["hair_color"]]) 
+map_chr(sw_people, ~ .x[["hair_color"]]) 
 
 # Is the character male?
-map_lgl(people, ~ .x[["gender"]] == "male") 
+map_lgl(sw_people, ~ .x[["gender"]] == "male") 
 
 # How heavy is each character?
-map_dbl(people, ~ .x[["mass"]])
+map_dbl(sw_people, ~ .x[["mass"]])
 # Doesn't work...because we get a string back
-map(people, ~ .x[["mass"]])
+map(sw_people, ~ .x[["mass"]])
 
 # A little risky
-map_dbl(people, ~ as.numeric(.x[["mass"]]))
+map_dbl(sw_people, ~ as.numeric(.x[["mass"]]))
 
 # Probably want something like:
-map_chr(people, ~ .x[["mass"]]) %>%
+map_chr(sw_people, ~ .x[["mass"]]) %>%
   readr::parse_number(na = "unknown")
 
diff --git a/03-challenges.R b/03-challenges.R
@@ -1,25 +1,29 @@
 # Star wars challenges
 library(purrr)
-
-# loads objects: films, people, vehicles, starships, 
-# planets & species
-load("data/swapi.rda")
+library(repurrrsive)
 
 # Which film (see films) has the most characters?
-map(films, "characters") %>%
+map(sw_films, "characters") %>%
   map_int(length) %>%
-  set_names(map_chr(films, "title")) %>%
+  set_names(map_chr(sw_films, "title")) %>%
   sort()
 
-# Create the planet_lookup vector from earlier.
-planet_lookup <- map_chr(planets, "name") %>% 
-  set_names(map(planets, "url"))
-
 # Which species has the most possible eye colors?
-species[[1]]$eye_colors
+sw_species[[1]]$eye_colors
 
-map_chr(species, "eye_colors") %>%
+map_chr(sw_species, "eye_colors") %>%
   strsplit(", ") %>%
-  map_int(length)
+  map_int(length) %>%
+  set_names(map_chr(sw_species, "name"))
 # this is lazy, what about n/a and unknown?
 
+# Which planets do we know the least about?
+# For one, entry 61
+map_lgl(sw_planets[[61]], ~ "unknown" %in% .x) %>%
+  sum()
+
+# For all
+map_int(sw_planets, 
+  ~ map_lgl(.x, ~ "unknown" %in% .x) %>% sum()) %>%
+  set_names(map_chr(sw_planets, "name")) %>%
+  sort(decreasing = TRUE)
diff --git a/04-other-iteration.R b/04-other-iteration.R
diff --git a/04-purrr-list-columns.R b/04-purrr-list-columns.R
diff --git a/05-purrr-list-columns.R b/05-purrr-list-columns.R
@@ -0,0 +1,44 @@
+# star wars people list to data frame
+library(tidyverse)
+library(repurrrsive)
+
+# A useful lookup table -----------------------------------------------
+film_number_lookup <- map_chr(sw_films, "url") %>%
+  map(~ stringr::str_split_fixed(.x, "/", 7)[, 6])  %>%
+  as.numeric() %>%
+  set_names(map_chr(sw_films, "url"))
+
+# Putting a few vars in a tibble --------------------------------------
+people_tbl <- tibble(
+  name    = sw_people %>% map_chr("name"), 
+  films   = sw_people %>% map("films"),
+  height  = sw_people %>% map_chr("height") %>% 
+    readr::parse_number(na = "unknown"),
+  species = sw_people %>% map_chr("species", .null = NA_character_)
+)
+
+# Turning parts of our list to a tibble -----------------------------------
+people_tbl$films
+
+# Use map with mutate to manipulate list columns
+people_tbl <- people_tbl %>%
+  mutate(
+    film_numbers = map(films, 
+      ~ film_number_lookup[.x]),
+    n_films = map_int(films, length)
+  )
+    
+people_tbl %>% select(name, film_numbers, n_films)
+
+
+# Your Turn ---------------------------------------------------------------
+
+# Create a new character column that collapses the film numbers in a single string,
+# e.g. for Luke " 6, 3, 2, 1, 7"
+
+people_tbl <- people_tbl %>% 
+  mutate(films_squashed = map_chr(film_numbers, paste, 
+    collapse = ", "))
+
+people_tbl %>% select(name, n_films, films_squashed)
+
diff --git a/README.md b/README.md
@@ -1,6 +1,6 @@
 # A purrr tutorial
 
-This repo hosts the materials for a [purrr](http://purrr.tidyverse.org/) tutorial.
+This repo hosts the materials for a [purrr](http://purrr.tidyverse.org/) tutorial.  The materials currently reflect the version planned for the Cascadia R Conf, Portland, OR Jun 2017.
 
 ## Upcoming in-person tutorials
 
@@ -13,16 +13,39 @@ Older versions of the materials, from prior in-person tutorials, are also availa
 * [rstudio::conf Jan 2017 (2.25 hours)](https://github.com/cwickham/purrr-tutorial/tree/v0.1)
 
 
-
-
-## Abstract
-
-Happy R users purrr: using functional programming to solve iteration problems
+## Outline
 
 Code with a lot of duplication is harder to understand, troubleshoot and maintain. The goal of this tutorial is help you remove duplication in your code by using functions that write `for` loops for you.
 
 You'll learn to use the functions in the `purrr` package to perform iterative tasks: tasks that look like "for each _____ do _____".
 
 By the end of the tutorial you'll be writing code that is more readable and easier to update and you'll be ready to solve new iteration problems faster and with fewer mistakes.
 
+## Learning Objectives
+
+By the end of the tutorial, you'll be able to:
+
+* Move from solving a problem on a single element, to iterating that solution over many elements with `map()`.
+* Identify when to use the typed variants of `map()`: `map_lgl()`, `map_int()`, `walk()` etc.
+* Iterate over two arguments with `map2()`.
+* Leverage `purrr` to get list data into tibbles.
+* Use `purrr` to work with list columns in tibbles.
+
+## Pre-requisites
+
+Don't worry if you have never written a `for` loop, used `lapply()`, written your own function or heard of a `tibble`, this tutorial is designed to be accessible to beginners.  
+
+That said, you should be familiar with exploring and subsetting the basic data structures in R including lists and data frames. 
+
+This is a hands-on tutorial, you'll need your laptop with R installed, as well as a few packages:
+
+```{r}
+install.packages("tidyverse")
+
+# install.packages("devtools")
+devtools::install_github("jennybc/repurrrsive")
+```
+
+## License
+
 <a rel="license" href="http://creativecommons.org/licenses/by-nc/4.0/"><img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by-nc/4.0/80x15.png" /></a><br />This <span xmlns:dct="http://purl.org/dc/terms/" property="dct:title">purrr tutorial</span> by <a xmlns:cc="http://creativecommons.org/ns#" href="https://github.com/cwickham/purrr-tutorial" property="cc:attributionName" rel="cc:attributionURL">Charlotte Wickham</a> is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-nc/4.0/">Creative Commons Attribution-NonCommercial 4.0 International License</a>.
