Create accidents.R

New file to play with accidents data from TfL API and population data from: https://data.london.gov.uk/dataset/office-national-statistics-ons-population-estimates-borough

R/accidents/accidents.R

@@ -0,0 +1,59 @@
+# Step 0 - prep -----------------------------------------------------------
+library(tidyverse)
+library(forcats)
+library(httr)
+library(jsonlite)
+library(readr)
+
+credentials <- list(app_id = tfl_app_id, app_key = tfl_app_key)
+
+# Step 1 - get data -------------------------------------------------------
+# Accidents
+url <- "https://api.tfl.gov.uk/AccidentStats/2015"
+req <- GET(url, query = credentials)
+accidents <- req %>% 
+  content("text") %>% 
+  fromJSON() %>% 
+  as_data_frame()
+
+
+pop <- read_csv("./api/population-estimates-single-year-age.csv")
+colnames(pop) <- colnames(pop) %>% tolower()
+
+# Step 2 - prep data ------------------------------------------------------
+accidents <- accidents %>% 
+  mutate(severity = as.factor(severity),
+         borough = as.factor(borough),
+         severity = fct_infreq(severity),
+         borough= fct_infreq(borough)) %>% 
+  select(borough, severity, lat, lon, location, date) %>% 
+  mutate(date_cln = gsub("T", " ", date),
+         date_cln = gsub("Z", " ", date_cln),
+         date_cln = lubridate::ymd_hms(date_cln))
+
+pop <- pop %>% 
+  filter(year == 2014) %>% 
+  select(borough, `all persons`) %>% 
+  rename(persons = `all persons`)
+
+joined <- accidents %>% 
+  left_join(pop)
+
+joined %>% 
+  group_by(borough) %>% 
+  summarise(total_incidents = n(),
+            persons = mean(persons)) %>% 
+  na.omit() %>% 
+  mutate(rate = total_incidents / persons) %>% 
+  ggplot(aes(x = persons, y = total_incidents, colour = total_incidents)) +
+  geom_point(size = 4) +
+  geom_smooth()
+
+# Step 3 - plot -----------------------------------------------------------
+accidents %>% 
+  ggplot(aes(x = fct_rev(borough))) +
+  geom_bar(aes(fill = severity), colour = "white") +
+  scale_fill_brewer(palette = "Dark2") +
+  coord_flip() +
+  theme_minimal()
+