Eric In line with my earlier posts, I would like to think of Babel codeblocks filters that take as a textual content and produce another textual content. Think of babel codeblocks as indeed custom exporters.
Power of Babel is the flexibility that the user gets in associating different code blocks with the same content and have different representations produced for the same. Let's revisit the original example. Let me walk through the whole sequence ... # Input Textual Content # User need not say that the content is table. It is obvious. In other # words babel is dynamically typed and tables are one of the primitive # datatypes within Babel runtime environment. Name of the table is the # name of the headline. * tableTestBabel | 0 | 4.40 | | 30 | 4.54 | | 60 | 7.09 | | 90 | 9.40 | | 120 | 9.22 | | 150 | 6.65 | | 180 | 4.22 | # Output Textual Content testBabel.pdf # Babel block named 'charPolAngle' is the custom exporter which would # act on the input text and produce an output text. # Note that the signature of the chartPolAngle and the use of a reserved # babel keyword 'this' which stand for the input textual content. #+srcname: chartPolAngle() #+begin_src R angle <- this[,1] energy <- this[,2] plot(angle,energy) energy.model <- nls (energy ~ a1 + a2 * (sin(pi / a3 *(angle-a4)))^2, start=list(a1=3.0, a2=7.0, a3=180, a4=0.0)) lines(spline(angle, fitted.values(energy.model)), lwd=2) summary(energy.model) #+end_src # To make a call, the user executes the headline and passes it the # custom routine. # Transform text <<tableTestBabel (:fmt chartPolAngle)>> ^^^^^^^^^^^^^ With this shift in call syntax one could do these with obvious interpretation. <<tabletestBabel>> # identity mapping <<tabletestBabel (:fmt csv)>> # map to csv <<tabletestBabel (:fmt latex)>> # map to latex To summarize Babel srcnames takes the following params as a must (they could be implicit) 1. A 'this' parameterw which is input text content. An headline entry in the above example. A babel invocation line takes a ':fmt ' param. It could be one of the inbuilt exporters like text, org, latex, pdf etc or left unspecified if the babel srcblock always produces only one format. It would also be usefult to specify how the transformed text is handled by a babel srcblock. Let's denote this param as :results If :results is nil then the exporter creates a side-effect. i.e., it produces a pdf file. If :results is inline then output text content is inserted inline i.e., wherever the macro invocation occurs. If :results is a Org Headline then output text content is inserted in that headline. To summarize, Babel macros acts on text blocks and produces text blocks. A babel macro with names outfmt is invoked as <<org headline (:fmt outfmt :results X)>> or as [[outfmt][input text content]] Let me know if you have questions. My lack of understanding of Babel's internals prevents me from being more specific or anticipate the issues involved. Nevertheless a shift in perspective from babel-src(intxt) to intxt(babel-src) is what is required. I invite you to go through my earlier mails[1]. Each one of them takes examples that have already surfaced in the mailing list and tries to reconcile what the user likes to accomplish with Babel macros with what the Org's existing world view is. Let me know whether or not I make sense. ps: I haven't really tried to address issues reported by the original poster. I need to have a buyin from you on what I am proposing before I am willing to put that effort. [1] http://article.gmane.org/gmane.emacs.orgmode/30040 Jambunathan K. > > #+call: chartPolAngle[:session testBabel :file > testBabel.pdf](pol=tableTestBabel) > > I'd be interested to hear what the community thinks of this new syntax. > > As an unrelated note, we also need to think of a natural way to allow > the header argument portion of a code block to span multiple lines. > > Best -- Eric > > Christopher Witte <ch...@witte.net.au> writes: > >> I'm having a bit of trouble with org bable and R. When I try to execute the >> code below (C-c C-c on the call line), as you can see, I get the results >> :nil >> >> --------------------------------------- >> #+tblname: tableTestBabel >> | 0 | 4.40 | >> | 30 | 4.54 | >> | 60 | 7.09 | >> | 90 | 9.40 | >> | 120 | 9.22 | >> | 150 | 6.65 | >> | 180 | 4.22 | >> >> #+srcname: chartPolAngle(pol) >> #+begin_src R >> angle <- pol[,1] >> energy <- pol[,2] >> plot(angle,energy) >> energy.model <- nls (energy ~ a1 + a2 * (sin(pi / a3 *(angle-a4)))^2, >> start=list(a1=3.0, a2=7.0, a3=180, a4=0.0)) >> lines(spline(angle, fitted.values(energy.model)), lwd=2) >> summary(energy.model) >> #+end_src >> >> #+call: chartPolAngle(pol=tableTestBabel) :session testBabel :file >> testBabel.pdf >> >> #+results: chartPolAngle(pol=tableTestBabel) >> : nil >> ------------------------------------ >> >> but If I move the header arguments to the source block, as in the code >> below, everything works fine. I also get asked "ESS [S(R): R] starting data >> directory? ~/doc/org/" which I don't get with the code above. >> >> --------------------------------------- >> #+tblname: tableTestBabel >> | 0 | 4.40 | >> | 30 | 4.54 | >> | 60 | 7.09 | >> | 90 | 9.40 | >> | 120 | 9.22 | >> | 150 | 6.65 | >> | 180 | 4.22 | >> >> #+call: chartPolAngle(pol=tableTestBabel) >> >> #+results: chartPolAngle(pol=tableTestBabel) >> : testBabel.pdf >> >> >> #+srcname: chartPolAngle(pol) >> #+begin_src R :session testBabel :file testBabel.pdf >> angle <- pol[,1] >> energy <- pol[,2] >> plot(angle,energy) >> energy.model <- nls (energy ~ a1 + a2 * (sin(pi / a3 *(angle-a4)))^2, >> start=list(a1=3.0, a2=7.0, a3=180, a4=0.0)) >> lines(spline(angle, fitted.values(energy.model)), lwd=2) >> summary(energy.model) >> #+end_src >> --------------------------------------- >> >> Org doesn't appear to respect the head arguments on the call. I pulled from >> git a couple days ago. Any ideas why? >> >> Cheers >> Chris Witte >> _______________________________________________ >> Emacs-orgmode mailing list >> Please use `Reply All' to send replies to the list. >> Emacs-orgmode@gnu.org >> http://lists.gnu.org/mailman/listinfo/emacs-orgmode > > _______________________________________________ > Emacs-orgmode mailing list > Please use `Reply All' to send replies to the list. > Emacs-orgmode@gnu.org > http://lists.gnu.org/mailman/listinfo/emacs-orgmode _______________________________________________ Emacs-orgmode mailing list Please use `Reply All' to send replies to the list. Emacs-orgmode@gnu.org http://lists.gnu.org/mailman/listinfo/emacs-orgmode
