West Philly crime heatmap code in R

west-philly-uc-2018-crime-heatmap.R

library(data.table)
library(lubridate)
library(dplyr)
library(ggmap)

# Data: https://www.opendataphilly.org/dataset/crime-incidents

philly <- fread("data/incidents.csv",
                select = c("location_block","text_general_code","dispatch_time","dispatch_date", "lat","lng"))

# Create variable with year
philly$year <- year(philly$dispatch_date)

# Subset incidents in West Philly / University City
philly_subset <- philly[philly$lat < 39.966 & philly$lat > 39.942 & philly$lng > -75.25 & philly$lng < -75.19,]

philly_subset %>%
  # Subsetting
  filter(text_general_code %in% c("Other Assaults",
                                  "Aggravated Assault No Firearm",
                                  "Robbery Firearm")) %>% 
  # Plotting
  qmplot(lng, lat, data = ., geom = "blank", 
         zoom = 15, maptype = "toner", darken = 0.1, legend = "topright") +
  stat_density_2d(aes(fill = ..level..), geom = "polygon", alpha = .3, color = NA) +
  scale_fill_gradient2("Assault and Robbery\nIncidents in 2018:", low = "green", mid = "yellow", high = "red", midpoint = 1000) +
  theme(legend.position="none")

ggsave(filename = "west-philly-uc-2018-crime-map.png",width = 10, height = 6)