Headline: Decade-old Sweave limitation removed in 5 minutes.+Yihui Xie
is doing some great things with knitr.
The inability to hide chunks dynamically was always a big annoyance with Sweave, especially with figures. Yes, there were LaTeX hacks, and other weavers, but knitr offers a real solution using traditional syntax. All it took was me asking for it.
Below is a toy example, but you can see the possibilities in terms of developing truly dynamic reproducible reports:
print("I am not even doing this!")
print("I am doing this!")
print("I am doing this and showing you how!")