R code: # group_by / nest / mutate /unnest ## demonstrates an idiom that I tend to forget the details of

unnest_united_nations_data_frame.R

# from the datacamp course 
# 'Exploratory Data Analysis in R: Case Study'
# by David Robinson
#
# this gist demonstrates an idiom  that I tend to forget the details of
#  group_by / nest / model /unnest 
#
# Load purrr, tidyr, and broom
library(purrr)
library(tidyr)
library(broom)

#  by_country_year_topic is already grouped
by_country_year_topic

# Fit model on the by_country_year_topic dataset
country_topic_coefficients <- by_country_year_topic %>%
  nest(-country, -topic) %>%
  mutate(model = map(data, ~ lm(percent_yes ~ year, data = .)),
         tidied = map(model, tidy)) %>%
  unnest(tidied)