mages' blog

Last week I was invited to give an introduction to googleVis at Lancaster University. This time I decided to use the R package slidify for my talk. Slidify, like knitr, is built on Markdown and makes it very easy to create beautiful HTML5 presentations.

Introduction to googleVis

Separating content from layout is always a good idea. Markup languages such as TeX/LaTeX or HTML are built on this principle. Ramnath Vaidyanathan has done a fantastic job with slidify, as it is very straightforward to create presentations with R. There are a couple of advantages compared to traditional presentation software packages:

• RMarkdown helps me to focus on the content
• Integration of R code is build in
• HTML5 allows me to embed interactive content, such as
  
  • Videos
  • googleVis and other interactive charts
  • shiny apps (more on this next week)

In the past I have used knitr in combination with pandoc to generate a slidy presentation. However, with slidfiy I can do all this in R directly. And better, Ramnath provides me with a choice of different layout frameworks and syntax highlighting options. Finally to top it all, publishing the slides on Github was only one more R statement: publish('mages', 'Introduction_to_googleVis').

I will give a half-day tutorial on googleVis with Diego de Castillo at useR2013! in Albacete on 9 July 2013. I hope to see some of you there.

After last week's kerfuffle I hope the roll out of googleVis version 0.3.2 will be smooth. To test the water I release this version into the wild here and if it doesn't get shot down in the next days, then I shall try to upload it to CRAN. I am mindful of the CRAN policy, so please get in touch or add comments below if you find any show stoppers.

So what's new in googleVis 0.3.2?

The default behaviour of the functions print.gvis and plot.gvis can be set via options().

Now this doesn't sound too exciting but it can be tremendously helpful when you write Markdown files for knitr. Here is why:

The third Cologne R user meeting took place last Friday, 5 October 2012, at the Institute of Sociology.

The evening was sponsored by Revolution Analytics, who provided funding which went towards the Kölner R user group Meetup page. We had a good turn-out with 18 participants showing up and three talks by Dominik Liebl, Jonas Stein and Sarah Westrop.

Photos: Günter Faes

Every year the UK’s general insurance actuarial community organises a big conference, which they call GIRO, short for General Insurance Research Organising committee.

This year's conference is in Brussels from 18 - 21 September 2012. Despite the fact that Brussels is actually in Belgium the UK actuaries will travel all the way to enjoy good beer and great talks.

On Wednesday morning I will run a session on Using R in insurance. It would be great to see some of you there.


I prepared the slides with R, RStudio, knitr, pandoc and slidy again. My title page shows a word cloud about the GIRO conference. It uses the wordcloud package and was inspired by Ian Fellows' post on FellStats.

The last slide shows the output of sessionInfo(). I am sure it will become helpful one day, when I have to remind myself how I actually created the slides and which packages and versions I used.

Today I feel very lucky, as I have been invited to the Royal Statistical Society conference to give a tutorial on interactive web graphs with R and googleVis.

I prepared my slides with RStudio, knitr, pandoc and slidy, similar to my Cambridge R talk. You can access the RSS slides online here and you find the original R-Markdown file on github. You will notice some HTML code in the file, which I had to use to overcome my knowledge gaps of Markdown or its limitations. However, my output format will always be HTML, so that should be ok. To convert the Rmd-file into a HTML slidy presentation execute the following statements on the command line:

Rscript -e "library(knitr); knit('googleVis_at_RSS_2012.Rmd')"
pandoc -s -S -i -t slidy --mathjax googleVis_at_RSS_2012.md 
  -o googleVis_at_RSS_2012.html

The next version of the googleVis package has been released on the project site and CRAN.

This version provides updates to the package vignette and a new example for the gvisMerge function. The new sections of the vignette have been featured on this blog in more detail earlier:

• Using googleVis with knitr (Link to post)
  
• Using Rook with googleVis (Link to post)
  
• Using Reduce with gvisMerge to display several charts on a page (Link to post)
  

Tonight I will give a talk at the Cambridge R user group about googleVis. Following my good experience with knitr and RStudio to create interactive reports, I thought that I should try to create the slides in the same way as well.

Christopher Gandrud's recent post reminded me of deck.js, a JavaScript library for interactive html slides, which I have used in the past, but as Christopher experienced, it is currently not that straightforward to use with R and knitr.

Thus, I decided to try slidy in combination with knitr and pandoc. And it worked nicely.

I used RStudio again to edit my Rmd-file and knitr to generate the Markdown md-file output. Following this I run pandoc on the command line to convert the md-file into a single slidy html-file:

pandoc -s -S -i -t slidy --mathjax Cambridge_R_googleVis_with_knitr_and_RStudio_May_2012.md -o Cambridge_R_googleVis_with_knitr_and_RStudio_May_2012.html

Et volià, here is the result:

Addition (2 June 2012)

Oh boy, knitr and Markdown are hitting a nail. With slidify by Ramnath Vaidyanathan another project sprung up to ease the creation of web presentations.

Last Saturday I met the guys from RStudio at the R in Finance conference in Chicago. I was curious to find out what RStudio could offer. In the past I have used mostly Emacs + ESS for editing R files. Well, and what a surprise it was. JJ, Joe and Josh showed me a preview of version 0.96 of their software, which adds a close integration of Sweave and knitr to RStudio, helping to create dynamic web reports with the new R Markdown and R HTML formats more easily.

Screen shot of RStudio with a knitr file (*.Rmd) in the top left window. Notice also the integrated knitr button.

You probably have come across Sweave in the past, but knitr is a fairly new package by Yihui Xie that brings literate programming to a new level. In particular the markdown approach allows me to create web content really quickly, without worrying to much about layout and R formatting. I begin to wonder if PDF and paper will be replaced by tablets and HTML5 in the future.

Here is a simple example. The knitr source code is available on Github.