The script imports Philadelphia Crime Data Parts I and II (https://www.opendataphilly.org/dataset/crime-incidents), creates a summary based on year, month, and crime type and creates a basic map in leaflet using the first 1000 incidents

PhlCrime_GettingStarted_PT_I_II.R

# the following script will import Philadelphia Crime Data
# Parts I and II, create a summary based on year, month, and crime type
# and will create a basic map in leaflet using the first 1000 incidents
# you will need to install dplyr, leaflet, readr, lubridate, and stringr
# packages ( install.packages('package name') )

rm(list = ls())
library(dplyr)
library(leaflet)
library(readr)
library(lubridate)
library(stringr)

# import data ####
ds <- read_csv('https://data.phila.gov/api/views/7ret-xhtc/rows.csv?accessType=DOWNLOAD')

# rename columns
names(ds)[c(3,6,7)] <- c('Dispatch.Date.Time', 'UCR.Code', 'General.Crime.Category')
# convert date objects
ds$Dispatch.Date.Time <- mdy_hms(ds$Dispatch.Date.Time)

# identify month and year of occurence
ds$month         <- month(ds$Dispatch.Date.Time)
ds$year          <- year(ds$Dispatch.Date.Time)


# incident counts by type, month, and year ####
crime.summary <-  ds %>% group_by(General.Crime.Category,
                                           month, year) %>% 
  summarise(
    events = n()
  )


# MAP ####

# create a data frame of the coordinates
ds$Coordinates<- gsub(")", "", ds$Coordinates)
ds$Coordinates<- gsub("\\(", "", ds$Coordinates)
coord.list <- (str_split(ds$Coordinates, ","))
ds$lat <- as.numeric(unlist(lapply(coord.list, function(x)x[1])))
ds$lon <- as.numeric(unlist(lapply(coord.list, function(x)x[2])))


# map the first 1000 incidents in the data set
# remove any missing coordinates
n <- 1000
coordinates <- na.omit(ds[1:n, ])

leaflet() %>%
  addProviderTiles('CartoDB.Positron') %>%
  setView(lng=-75.16048, lat=39.99000, zoom =11) %>%
  addCircles(lat = coordinates$lat, lng = coordinates$lon,
             fillOpacity = 0.8 , opacity = 0.8, radius = 8, weight = 1,
             popup = paste("Crime Category:",coordinates$General.Crime.Category, "<br/> Time:", coordinates$Dispatch.Date))