standalone figures (pdf + png) and beamer slides

I have reproduced all the book figures. They come in standalone pdf and png format. Other formats can be created from the 'knitr' source as desired. A set of beamer slides with each figure (plus a small number of extra ones) is created by knitr. An example of presentation based on Thomas Piketty's 26 November 2014 Sao Paulo  powerpoint is also included. In the process I rewrote the data import, as I found I needed to understand where the data had come from in the spreadsheets (not because I did it better, I didn't).  I have saved the dataframes for convenience. For instance, Figure 1.1 is produced by the code chunk labeled Figure_1_1 with the dataframe named df_1_1 and is saved as Figure_1_1.pdf and Figure_1_1.png. 

The README.md file lists the file in the repository named 'Slides'. There are some issues with the dual-axis plots, which I intend to fix shortly. I noticed that some figures were missing from the master repository, so my code may be useful in filling the gaps. I have not covered the tables. All the figures were generated with ggplot, though I intend to produce some rCharts too for some selected figures (the ones that have more than 5 series on them). Comments welcome, naturally!