A map of the Divvy stations in Chicago

Read the data

As before, I use function read.divvy.data to read the trip and station data from the CSV files.

divvy <- read.divvy.data()
# Reading station data from ../data/Divvy_Stations_2016_Q4.csv.
# Reading trip data from ../data/Divvy_Trips_2016_Q1.csv.
# Reading trip data from ../data/Divvy_Trips_2016_04.csv.
# Reading trip data from ../data/Divvy_Trips_2016_05.csv.
# Reading trip data from ../data/Divvy_Trips_2016_06.csv.
# Reading trip data from ../data/Divvy_Trips_2016_Q3.csv.
# Reading trip data from ../data/Divvy_Trips_2016_Q4.csv.
# Preparing Divvy data for analysis in R.
# Converting dates and times.

Get total number of departures by station

I use the trip data to get the total number of departures by station. From these data, I create a “departures” column.

divvy$stations <-
  cbind(divvy$stations,
    data.frame(departures = as.vector(table(divvy$trips$from_station_id))))
head(divvy$stations)
#                           name latitude longitude dpcapacity online_date
# 456        2112 W Peterson Ave 41.99118 -87.68359         15   5/12/2015
# 101              63rd St Beach 41.78102 -87.57612         23   4/20/2015
# 109          900 W Harrison St 41.87468 -87.65002         19    8/6/2013
# 21  Aberdeen St & Jackson Blvd 41.87773 -87.65479         15   6/21/2013
# 80     Aberdeen St & Monroe St 41.88042 -87.65560         19   6/26/2013
# 346   Ada St & Washington Blvd 41.88283 -87.66121         15  10/10/2013
#     departures
# 456        500
# 101       1068
# 109       4813
# 21        9425
# 80       10577
# 346       8480
summary(divvy$stations$departures)
#    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
#       1     557    3058    6188    9029   90042

Create a Divvy stations map

A plot of the Divvy stations by geographic location (latitude and longitude) traces the outlines of the City of Chicago and the Lake Michigan shore. Further, the location of the downtown is apparent by scaling the area of each circle by the number of trips.

The University of Chicago Divvy station is highlighted in red.

divvy$stations <-
  transform(divvy$stations,
            at.uchicago = (name == "University Ave & 57th St"))
ggplot(divvy$stations,aes(x    = longitude,
                          y    = latitude,
                          fill = at.uchicago,
                          size = sqrt(departures))) +
  geom_point(shape = 21,color = "white") +
  scale_fill_manual(values = c("darkblue","red")) +
  theme_minimal() +
  theme(panel.grid.major = element_blank(),
        panel.grid.minor = element_blank())

Past versions of create-stations-map-1.png

Session information

sessionInfo()
# R version 3.4.3 (2017-11-30)
# Platform: x86_64-apple-darwin15.6.0 (64-bit)
# Running under: macOS High Sierra 10.13.6
# 
# Matrix products: default
# BLAS: /Library/Frameworks/R.framework/Versions/3.4/Resources/lib/libRblas.0.dylib
# LAPACK: /Library/Frameworks/R.framework/Versions/3.4/Resources/lib/libRlapack.dylib
# 
# locale:
# [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
# 
# attached base packages:
# [1] stats     graphics  grDevices utils     datasets  methods   base     
# 
# other attached packages:
# [1] ggplot2_3.1.0     data.table_1.11.4
# 
# loaded via a namespace (and not attached):
#  [1] Rcpp_1.0.0           knitr_1.20           whisker_0.3-2       
#  [4] magrittr_1.5         workflowr_1.2.0.9000 tidyselect_0.2.5    
#  [7] munsell_0.4.3        colorspace_1.4-0     R6_2.2.2            
# [10] rlang_0.3.1          dplyr_0.8.0.1        stringr_1.3.1       
# [13] plyr_1.8.4           tools_3.4.3          grid_3.4.3          
# [16] gtable_0.2.0         withr_2.1.2          git2r_0.23.3        
# [19] htmltools_0.3.6      assertthat_0.2.0     yaml_2.2.0          
# [22] lazyeval_0.2.1       rprojroot_1.3-2      digest_0.6.17       
# [25] tibble_2.1.1         crayon_1.3.4         purrr_0.2.5         
# [28] fs_1.2.6             glue_1.3.0           evaluate_0.11       
# [31] rmarkdown_1.10       labeling_0.3         stringi_1.2.4       
# [34] pillar_1.3.1         compiler_3.4.3       scales_0.5.0        
# [37] backports_1.1.2      pkgconfig_2.0.2