Creating abstract city maps for Leaflet usage

Leaflet is a great way to display spatial information in an interactive way. If you want to display the difference between different neighborhoods you would usually get the proper shapefiles on the web and connect your data to them. But sometimes it does not need detailed shapefiles and you want more abstraction to get your information across. I came up with the idea to draw my own little simplified polygons to get an abstract map of Hamburg.

AbtractHHtool

There are some great and free tools on the web to create your own polygons. I was using click2shp. You are just going to draw your polygons on a google map and afterwards you can export your polygons as a shapefile to use them from within R. Down below you find a little R script to display your polygons in a Shiny App.

#############################################################################################################################################
# PACKAGES
#############################################################################################################################################

require(leaflet)
require(shinythemes)
require(rgdal)
require(maptools)
require(rmapshaper)
require(shiny)
require(leaflet.extras)

#############################################################################################################################################
# UI
#############################################################################################################################################

shinyUI(
bootstrapPage(theme = shinytheme("united"),
 navbarPage(title="Where to live in Hamburg?",
 tabPanel("Karte",
 div(class="outer",

tags$style(type = "text/css", ".outer {position: fixed; top: 50px; left: 0; right: 0; bottom: 0; overflow: hidden; padding: 0}"),

leafletOutput("mymap", width = "100%", height = "100%")
)))))

#############################################################################################################################################
# SERVER
#############################################################################################################################################

shinyServer(
function(input, output, session) {

# setwd
setwd("YourPath")

# load your own shapes
hhshape <- readOGR(dsn = ".", layer = "click2shp_out_poly")

# load some data (could be anything)
data <- read.csv("anwohner.csv", sep = ";", header = T)
rownames(data) <- data$ID
hhshape <- SpatialPolygonsDataFrame(hhshape, data)

# remove rivers from sp file
hhshape <- hhshape[!(hhshape$Stadtteil %in% c("Alster","Elbe","Nix")), ]

# create a continuous palette function
pal <- colorNumeric(
 palette = "Blues",
 domain = hhshape@data$Anwohner
)

# plot map
output$mymap <- renderLeaflet({ leaflet(options = leafletOptions(zoomControl = FALSE, minZoom = 11, maxZoom = 11, dragging = FALSE)) %>%
 setView(lng = 9.992924, lat = 53.55100, zoom = 11) %>%
 addPolygons(data = hhshape,
  fillColor = ~pal(hhshape@data$Anwohner), fillOpacity = 1, stroke = T, color = "white", opacity = 1, weight = 1.2, layerId = hhshape@data$ID,
  highlightOptions = highlightOptions(color= "grey", opacity = 1, fillColor = "grey", stroke = T, weight = 12, bringToFront = T, sendToBack = TRUE),
  label=~stringr::str_c(Stadtteil,' ',"Anwohner:",formatC(Sicherheit, big.mark = ',', format='d')),
  labelOptions= labelOptions(direction = 'auto'))
})
})

This little R Code will give you the following result.

AbtractHH

Make sure you check out my Github for other data driven projects.

Shiny App for cultural hackathon

Recently I took part at Coding Durer, a five days international and interdisciplinary hackathon for art history and information science. The goal of this hackathon is to bring art historians and information scientists together to work on data. It is kind of an extension to the cultural hackathon CodingDaVinci where I participated in the past. I also wrote an article about CDV on this blog.

Logo_CodingDurer_300dpi-1-300x164

At CodingDurer we developed a Shiny App to explore the genre of church interior paintings developed in the Netherlands in the middle of the 17th century. There are hundreds of church interior paintings scattered across collections around the world. The research of this subject to date has focused mainly on particular artists or churches, rather than the overall genre and its network of artists and places. This project, born during the Coding Durer 2017, addresses this issue by providing a platform for further research on the paintings and creating an insight into the bigger picture of the genre for the first time. This visualization of over 200 paintings of 26 different churches by 16 different artists was created with the following research questions in mind:

  • In what places the artists were active and in what places did they depict church interior(s)?
  • Did the artists have ‘favourite’ church interiors?
  • In what places and when would the artists possibly meet?
  • What church interiors were depicted the most?
  • What church interiors were depicted by most artists?

durer1

The starting point of the project was a spreadsheet listing the paintings, artists, collections, etc. that was created for research purposes two years ago. This re-purposed data needed cleaning and additional information, e.g. IDs (artists, churches, paintings), locations (longitude, latitude), and stable URLs for images. You can see an image of the Shiny App above and try it out yourself here.

You can get the whole code on my Github along with other data driven projects.

Doing a Twitter Analysis with R

Recently I took part at Coding Durer, a five days international and interdisciplinary hackathon for art history and information science. The goal of this hackathon is to bring art historians and information scientists together to work on data. It is kind of an extension to the cultural hackathon CodingDaVinci where I participated in the past. There is also a blog post about CDV. I will write another blog post about the result of Coding Durer another day but this article is going to be a twitter analysis of the hashtag #codingdurer. This article was a very good start for me to do the analysis.

tumblr_inline_mn4aupdWkb1qz4rgp

First we want to get the tweets and we are going to use the awesome twitteR package. If you want to know how you can get the API key and stuff I recommend to visit this page here. If you have everything setup we are good to go. The code down below does the authentication with Twitter and loads our packages. I assume you know how to install a R package or at least find a solution on the web.

# get package
require(twitteR)
library(dplyr)
library(ggplot2)
library(tidytext)

# do auth
consumer_key <- "my_key"
consumer_secret <- "my_secret"
access_token <- "my_token"
access_secret <- "my_access_secret"

setup_twitter_oauth(consumer_key, consumer_secret, access_token, access_secret)

We are now going to search for all the tweets containing the hashtag #codingdurer using the searchTwitter function from the twitteR package. After converting the result to a easy-to-work-with data frame we are going to remove all the retweets from our results because we do not want any duplicated tweets. I also removed the links from the twitter text as we do not need them.

# get tweets
cd_twitter <- searchTwitter("#CodingDurer", n = 2000)
cd_twitter_df <- twListToDF(cd_twitter)

# remove retweets
cd_twitter_unique <- cd_twitter_df %>% filter(!isRetweet)

# remove link
cd_twitter_nolink <- cd_twitter_unique %>% mutate(text = gsub("https?://[\\w\\./]+", "", text, perl = TRUE))

With the code down below we are going to extract the twenty most active twitter accounts during Coding Durer. I used some simple ggplot for graphics and saved it to a variable called people.

# who is tweeting
people = cd_twitter_nolink %>%
count(screenName, sort = TRUE) %>% slice(1:20) %>%
ggplot(aes(x = reorder(screenName, n, function(n) -n), y = n)) +
ylab("Number of Tweets") +
xlab("") +
geom_bar(stat = "identity") +
theme(axis.text.x = element_text(angle = 45, hjust = 1)) +
ggtitle("Most active twitter users")

Now we want to know the twenty most used words from the tweets. This is going to be a bit trickier. First we extract all the words being said. Then we are going to remove all the stop words (and some special words like codingdurer, https …) as they are going to be uninteresting for us. We are also going to remove any twitter account name from the tweets. Now we are almost good to go. We are just doing some singularization and then we can save the top twenty words as a ggplot graphic in a variable called word.

# what is being said
tweet_words <- cd_twitter_nolink %>% select(id, text) %>% unnest_tokens(word, text)

# remove stop words
my_stop_words <- stop_words %>% select(-lexicon) %>% bind_rows(data.frame(word = c("codingdurer","https", "t.co", "amp")))
tweet_words_interesting <- tweet_words %>% anti_join(my_stop_words)

# remove name of tweeters
cd_twitter_df$screenName = tolower(cd_twitter_df$screenName)
tweet_words_interesting = filter(tweet_words_interesting, !(word %in% unique(cd_twitter_df$screenName)))

# singularize words
tweet_words_interesting$word2 = singularize(unlist(tokenize(tweet_words_interesting$word)))
tweet_words_interesting$word2[tweet_words_interesting$word2 == "datum"] = "data"
tweet_words_interesting$word2[tweet_words_interesting$word == "people"] = "people"

word = tweet_words_interesting %>%
count(word2, sort = TRUE) %>%
slice(1:20) %>%
ggplot(aes(x = reorder(word2, n, function(n) -n), y = n)) +
geom_bar(stat = "identity") +
theme(axis.text.x = element_text(angle = 45, hjust = 1)) +
ylab("Word Occurrence") +
xlab("") +
ggtitle("Most used words in tweets")

# plot all together
grid.arrange(people, word, nrow=2, top = "Twitter Analysis of #codingdurer")

The grid.arrange function let us plot both of our graphics at once. Now we can see who the most active twitter users were and what the most used words were. It is good to see words like art, data and project at the top.

C7cgPf9WwAAW4Dp

Make sure you check out my Github for other data driven projects.

How to import multiple data files (the fast way)

csv-logo

Sometimes you have your data stored in multiple csv files and want to load them into a single data frame in R. There are several answers on the web to this questions and I recently found a fast solution to this problem.

# packages
require(data.table)

# set wd
setwd("PathToYourFolder")

# import files
files = list.files(pattern="*.csv")
dataset = do.call(rbind, lapply(files, fread))
rm(files)

# transform data to df
dataset <- as.data.frame(unclass(dataset))

The code above uses both lapply and the cool fread function from the data.table package to load in your data in a quiet fast manner. I recommend to try out this approach if you dealing with long import times.

Make sure you check out my Github for other data driven projects.

How to import a subset of a (too huge) csv file

01_sqldf

Sometimes people create csv files that are just too huge to upload them into your R session while most of the times you just need a subset of this data set. Recently I tapped into this problem and first I tried to import the whole file with functions like fread or the classic read.csv but this did not help much as the file was just too big and my computer failed to import it. With the awesome read.csv.sql function from the sqldf package I found a good way to solve my problem. This function enables you to use SQL statements within the import function which make it possible to select only a subset of the file to reduce the import size.

mydata = read.csv.sql("mydata.csv", sql = "select * from file where City = '\"Hamburg\"' ", sep = ";")

The code above loads only those lines of the file in where the city is Hamburg. I still had trouble to with the encoding that is why I used this ugly string with backlashes in the SQL statement. I will leave it like this as you might having the same problem.

Make sure you check out my Github for other data driven projects.