Re: parameterizing keyword values during a #+call

[Greg Minshall <minshall@umich.edu>]

Eric,

just for completeness, and in case this may be of use to other people,
below is the result of my question + your suggestions.  the following
illustrates org-mode plus asymptote producing a .svg file during html
export, and a pdf file during any other (presumably, latex) export.

thanks again, Greg
----
# trying to get graphics that works for both latex/beamer and for html

# here's a suggestion from Eric Schulte
# http://article.gmane.org/gmane.emacs.orgmode/71301
# with this clarification
# http://article.gmane.org/gmane.emacs.orgmode/71393
# which produced the following

# we define an emacs lisp macro ext that produces a file extension
# of "svg" or "pdf" depending on whether we are exporting to html or
# to some other source.  this macro is called when computing the
# output file name argument in a call to an asymptote routine as in:
#
# #+call: rectangle[:file (ext twod-1)](TSIZE=1.0) :results file
#
# which calls an asymptote routine (defined in our file) called
# rectangle to produce a file called twod-1.svg or twod-1.pdf.

# define the ext emacs lisp macro (i think in the following you *need*
# ":exports results" -- instead of ":exports none" -- to make sure the
# code is executed during export; the ":results silent" keeps any
# output -- or nil -- from showing up in the output file.)

#+begin_src emacs-lisp :exports results :results silent
    (defmacro ext (base)
      (format "%s.%s" base
              (if (and (boundp 'backend) (equal backend 'html)) "svg" "pdf")))
#+end_src


# follows an example use of the above macro

# first, define a asymptote function (org-named "rectangle") that
# draws a rectangle
#+name: rectangle
#+begin_src asymptote :var TSIZE=1.0 :exports none
  import trembling;
  size(100);
  int off = 2, width = 100, height = 30;
  string tsize = format("%g", TSIZE);
  tremble tr0=tremble(angle=0);   // no trembling
  tremble tr10=tremble(angle=10,frequency=0.1,random=50,fuzz=1);
  
  picture rectangle(pair sw, pair ne, int offset, string text, tremble tr) {
    picture pic;
    path g =
      (sw.x+offset,sw.y+offset)--(ne.x-offset,sw.y+offset)--(ne.x-offset,ne.y-offset)--(sw.x+offset,ne.y-offset)--cycle;
    label(pic, text, ((sw.x+ne.x)/2, (sw.y+ne.y)/2));
    draw(pic, tr.deform(g));
    return pic;
  }
  
  add(rectangle((0,0),(width,height),0, "", tr0));
  add(rectangle((0,0),(width,height),off, tsize, tr10));
#+end_src

# now, invoke the above asymptote function, producing a file called
# either twod-1.svg or twod-1.pdf:

#+call: rectangle[:file (ext twod-1)](TSIZE=1.0) :results file

# now, you can C-c C-e l o or C-c C-e h o and see the image in the
# two formats

# $Id: parameterizing.org,v 1.2 2013/04/30 14:37:29 minshall Exp $