On Thu, 18 Jun 2015, Xebar Saram wrote:

> Thx Chuck
>
> this sounds great. could you perhaps point us to some documentation on
> this, or perhpas consider sharing a detailed overview of your workflow?
> this seems it could really fit my needs.

Start with Sections 1-3 of ox-ravel.org for basic info.

There are a couple of examples on my github repo. Looking at the 
ravel-lang branch[1], there are these files:

- example-1-Rnw.org :: contains an org mode translation of the
      “example-1.Rnw’ (Sweave) file from the R distribution and
      instructions on how to export it.


- knitr-minimal-rhtml.org :: contains the “knitr-minimal.Rhtml’ file
      from the knitr demos page, but modified to *.org format.


- demos.org :: contains a variety of examples. It is best viewed
      online using 'raw' (or by downloading and viewing it in Org mode),
      as github formatting masks the #+BEGIN_EXAMPLE ... #+END_EXAMPLE
      sections that show what the output should be.

As far as caching goes this file (named cache.org, say)

--8<---------------cut here---------------start------------->8---

* cache this chunk

#+ATTR_RAVEL: cache=TRUE
#+NAME: show-time
#+BEGIN_SRC R
   firstTime <- date()
   firstTime
#+END_SRC

--8<---------------cut here---------------end--------------->8---

when exported as ravel-latex (i.e. C-c C-e r l, if you have ox-ravel
up and running, see section 2 of ox-ravel.org) creates cache.Rnw with
one chunk for which caching is specified. Loading knitr and running
knit("cache.Rnw") in R produces cache.tex and 3 ./cache/show-time*
files. Rerunning cache.Rnw will not update those files even if
cache.Rnw is updated as long as the code in the show-time block is
unchanged. You can start a fresh session, run knit("cache.Rnw"), and
the value of firstTime will be loaded into it.

HTH,

Chuck

[1] https://github.com/chasberry/orgmode-accessories/tree/ravel-lang