Merge pull request #1 from drfinlayscott/master

Improved Figure 2
Merge pull request #2 from drfinlayscott/master

Finlay's latest changes
Changing vignette to use knitr
Fixing some errors in knitr vignette
Two typos corrected
Merge pull request #6 from gustavdelius/knitr

Using knitr for vignette