Re: [O] [babel] noweb reference with default values

[Charles C. Berry]

On Mon, 14 Dec 2015, Andreas Leha wrote:

> Hi all,
>
> I'd like to hear your ideas on how to include noweb references to code
> blocks in a way that the default values are used as parameter values.
>
> Here is a little example:
>
> #+PROPERTY: header-args:R :session *testR*
>
> The background is that I like to use Org mode table to record small data.
>
> #+name: datatable
> | A |  B |
> |---+----|
> | 1 | 10 |
> | 2 | 20 |
>
> Usually I want to pre-process and/or convert such data.
>
> #+name: read_datatable
> #+header: :var datatable=datatable
> #+begin_src R :results none
>  datatable$B <- 10 * datatable$B
> #+end_src
>
> Later I would like to use that data in larger (R-) code blocks.  I'd
> like such code blocks to DWIM:
>
> #+name: some_code
> #+begin_src R :noweb yes :results graphics :file testplot.png
>  <<read_datatable>>
>  plot(datatable$A, datatable$B)
> #+end_src
>
> But they do not: They are not stand alone and do not execute -- unless I
> executed `read_datatable' manually/by chance upfront.

Try this:

#+name: read_datatable
#+header: :var datatable=datatable
#+begin_src R :results value :colnames yes
  datatable$B <- 10 * datatable$B
  datatable
#+end_src

#+name: some_code
#+HEADER: :var datatable=read_datatable()
#+begin_src R :noweb yes :results graphics :file testplot.png
plot(datatable$A, datatable$B)
#+end_src


HTH,

Chuck