googleVis overview & developments

• A brief introduction to googleVis
• Recent developments
• How I created this presentation with RStudio
• Summary

• Inspired by Hans Rosling's talk and Gapminder we also wanted interactive data visualisation tools
• The software behind Hans' talk was bought by Google and integrated as motion charts into their Visualisation API
• Hence, we had to create googleVis, an R package and interface to the Google Chart Tools API
  • Development started in 2010

• Google Chart Tools provide a way to visualize data on web sites
• The API makes it easy to create interactive charts
• It uses JavaScript and DataTable / JSON as input
• Output is either HTML5/SVG or Flash
• Browser with internet connection required to display chart
• Please read the Google Terms of Service before you start

The chart code has five generic parts:

1. References to Google's AJAX and Visualisation API
2. Data to visualize as a DataTable
3. Instance call to create the chart
4. Method call to draw the chart including options
5. HTML <div> element to add the chart to the page

• The functions of the package allow users to visualize data with the Google Chart Tools without uploading their data to Google
• The output of googleVis functions is html code that contains the data and references to JavaScript functions hosted by Google
• To view the output a browser with an internet connection is required, the actual chart is rendered in the browser; some charts require Flash

• Flash based
  • Motion Charts, Annotated Time Lines, Geo Maps
• HMTL5/SVG based
  • Maps, Geo Charts and Intensity Maps,
  • Tables, Gauges, Tree Maps, Timelines,
  • Line-, Bar-, Column-, Area- and Combo Charts,
  • Scatter-, Bubble-, Candlestick-, Pie- and Org Charts,
  • Annotation-, Calendar-, Histogram and Sankey Charts
• Support for roles, trendlines and Shiny via renderGvis

plot(gvisMotionChart(Fruits, "Fruit", "Year"))

• Charts: 'gvis' + ChartType
• For a motion chart we have

M <- gvisMotionChart(data, 
                     idvar='id', 
                     timevar='date', 
                     options=list(), 
                     chartid)

• Display the chart by simply plotting the output: plot(M)
• Plot will generate a temporary html-file and open it in a new browser window

df <- data.frame(year=1:11, x=1:11)
plot(gvisScatterChart(df, options=list(width=600, height=400)))

df <- data.frame(label=c("US", "GB", "BR"), val1=c(1,3,4), val2=c(23,12,32))
Line <- gvisLineChart(df, xvar="label", yvar=c("val1","val2"),
        options=list(title="Hello World", legend="bottom",
                titleTextStyle="{color:'red', fontSize:18}",                         
                vAxis="{gridlines:{color:'red', count:3}}",
                hAxis="{title:'My Label', 
                        titleTextStyle:{color:'blue'}}",
                series="[{color:'green', targetAxisIndex: 0}, 
                         {color: 'blue',targetAxisIndex:1}]",
                vAxes="[{title:'Value 1 (%)', format:'##,######%'}, 
                                  {title:'Value 2 (\U00A3)'}]",                          
                curveType="function", width=500, height=300                         
                ))

Options in googleVis have to follow the Google Chart API options

plot(Line)

Plot countries' S&P credit rating sourced from Wikipedia

library(XML)
url <- "http://en.wikipedia.org/wiki/List_of_countries_by_credit_rating"
x <- readHTMLTable(readLines(url), which=3)
levels(x$Rating) <- substring(levels(x$Rating), 4, 
                            nchar(levels(x$Rating)))
x$Ranking <- x$Rating
levels(x$Ranking) <- nlevels(x$Rating):1
x$Ranking <- as.character(x$Ranking)
x$Rating <- paste(x$Country, x$Rating, sep=": ")
G <- gvisGeoChart(x, "Country", "Ranking", hovervar="Rating",
                options=
                  list(gvis.editor="S&P",
                       projection="kavrayskiy-vii",
                       colorAxis="{colors:['#91BFDB', '#FC8D59']}"))

plot(G)

• New functions gvisSankey, gvisAnnotationChart, gvisHistogram, gvisCalendar and gvisTimeline
  
• New demos and vigenttes for trendlines and roles
• New vignettes written in R Markdown
• Dynamic help pages with roxygen2
• Moved code development from Google Code with SVN to GitHub with git

df <- data.frame(year=1:11, x=1:11,
                 x.scope=c(rep(TRUE, 8), rep(FALSE, 3)),
                 y=11:1, y.html.tooltip=LETTERS[11:1],                 
                 y.certainty=c(rep(TRUE, 5), rep(FALSE, 6)),
                 y.emphasis=c(rep(FALSE, 4), rep(TRUE, 7)))
plot(gvisScatterChart(df,options=list(lineWidth=2, width=600, height=400)))

df <- data.frame(Adress=c("EC3M 7HA", "東京都新宿区北新宿2-21-1"),
                 Tip=c("Lloyd's", "Tokyo R User Group"))
plot(gvisMap(df, "Adress", "Tip",
              options=list(mapType='normal',
                icons="{'default': {'normal': 'http://icons.iconarchive.com/icons/icons-land/vista-map-markers/48/Map-Marker-Ball-Azure-icon.png',
                                               'selected': 'http://icons.iconarchive.com/icons/icons-land/vista-map-markers/48/Map-Marker-Ball-Right-Azure-icon.png'}
                                  }", width=800, height=250)))

dat <- data.frame(Room=c("Room 1","Room 2","Room 3"),
                  Language=c("Japanese", "English", "German"),
                  start=as.POSIXct(c("2014-04-17 14:00", 
                                     "2014-04-17 15:00",
                                     "2014-04-17 14:30")),
                  end=as.POSIXct(c("2014-04-17 15:00", 
                                   "2014-04-17 16:00",
                                   "2014-04-17 15:30")))
plot(gvisTimeline(data=dat, rowlabel="Room", barlabel="Language",
                  start="start", end="end", options=list(width=800, height=250)))

dat <- data.frame(From=c(rep("A",3), rep("B", 3)), 
                  To=c(rep(c("X", "Y", "Z"),2)),
                  Weight=c(5,7,6,2,9,4))
plot(gvisSankey(dat, from="From", to="To", weight="Weight",
                options=list(height=250)))

plot(gvisCalendar(Cairo, datevar="Date",
                  numvar="Temp",
                  options=list(calendar="{ cellSize: 10 }"))

xtable(tail(Stock, 3))

A <- gvisAnnotationChart(
  Stock, datevar="Date",
  numvar="Value", idvar="Device",
  titlevar="Title", 
  annotationvar="Annotation",
  options=list(displayAnnotations=TRUE,
               legendPosition='newRow',
               fill=10, displayExactValues=TRUE,
               colors="['#0000ff','#00ff00']",
               width=600, height=300)
  )

plot(A, tag='chart')

• Demonstartion of googleVis
  • Run demo(googleVis) to see examples of all charts
• Using the Google Chart Tools with R
• Using Roles via googleVis
• Using Trendlines with googleVis
• Markdown example with knitr and googleVis
• My googleVis blog posts

• Simply started a new presentation file in RStudio and wrote markdown
• Customised the CSS file
• Ensured googleVis output is included as html, e.g.

  {r setOptions, message=FALSE}
  library(googleVis)
  options(gvis.plot.tag="chart")
  

• Used results='asis' to display googleVis plot statements

  {r scatterchart, results="asis"}
  plot(gvisScatterChart(women))
  

• googleVis provides an interface to the Google Chart Tools
  • Arguments and parameters follow the Google API
  • Note, Flash charts are only displayed when hosted on a web server, or the local directory has been added as a trusted folder in the Adobe settings
• Alternative R packages are in development for interactive charts, e.g. rCharts, ggvis

Markus Gesmann and Diego de Castillo. Using the Google Visualisation API with R, The R Journal, 3(2):40-44, December 2011 and googleVis package vignette

R markdown code of this presentation is available on GitHub

sessionInfo()

R version 3.1.0 (2014-04-10)
Platform: x86_64-apple-darwin13.1.0 (64-bit)

locale:
[1] de_DE.UTF-8/de_DE.UTF-8/de_DE.UTF-8/C/de_DE.UTF-8/de_DE.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] XML_3.98-1.1    xtable_1.7-3    googleVis_0.5.2 knitr_1.5      

loaded via a namespace (and not attached):
[1] evaluate_0.5.5  formatR_0.10    RJSONIO_1.2-0.2 stringr_0.6.2  
[5] tools_3.1.0