Re: Tangled Latex code gives error

[Andreas Leha <andreas.leha@med.uni-goettingen.de>]

Hi Lawrence,

Lawrence Bottorff <borgauf@gmail.com> writes:
> I'm following the Latex howto of org-mode babel. Here's the snippet
> from the howto I've got in a separate .org file (see bottom of howto
> page):
>
> #+LATEX_HEADER: \usepackage{tikz}
>
> First execute the second code block, to define the convenience macro
> and to set the required new variables in ob-latex.el. Then export to
> HTML and to pdf to see the tree exported as an SVG image and as
> embedded tikz respectively.
>
> * Tikz test
> Here's a tree, exported to both html and pdf.
>
> #+header: :file (by-backend (html "tree.svg") (t 'nil))
> #+header: :imagemagick
> #+header: :results (by-backend (pdf "latex") (t "raw"))
> #+header: :tangle yes
> #+begin_src latex
> \usetikzlibrary{trees}
> \begin{tikzpicture}
> \node [circle, draw, fill=red!20] at (0,0) {1}
> child { node [circle, draw, fill=blue!30] {2}
> child { node [circle, draw, fill=green!30] {3} }
> child { node [circle, draw, fill=yellow!30] {4} }};
> \end{tikzpicture}
> #+end_src
>
> * COMMENT setup
> #+header: :tangle yes
> #+begin_src emacs-lisp :results silent
> (setq org-babel-latex-htlatex "htlatex")
> (defmacro by-backend (&rest body)
> `(case (if (boundp 'backend) (org-export-backend-name backend) nil) ,
> @body))
> #+end_src
>
> This doesn't really produce a .svg of the tree as advertised, but
> exporting to Latex does produce it just fine.

Works as advertised for me.  What version of orgmode are you using?
There has been a bug fix in that code recently.

Note, that in that example the :imagemagick flag is superfluous.  It is
necessary, for instance, if you want to be able to get a inline
displayable image in png as well.
Then, the example should be
--8<---------------cut here---------------start------------->8---
#+header: :file (by-backend (html "tree.svg") (t "tree.png"))
#+header: :imagemagick
#+header: :results (by-backend (pdf "latex") (t "raw"))
#+begin_src latex
  \usetikzlibrary{trees}
  \begin{tikzpicture}
    \node [circle, draw, fill=red!20] at (0,0) {1}
    child { node [circle, draw, fill=blue!30] {2}
      child { node [circle, draw, fill=green!30] {3} }
      child { node [circle, draw, fill=yellow!30] {4} }};
  \end{tikzpicture}
#+end_src
--8<---------------cut here---------------end--------------->8---



>
> My real confusion starts when I try to tangle the babel code blocks.
> The C-c C-v t command produces two separate files just fine, a .tex
> and .el, but then if I try to Run Latex on the .tex file just by
> itself it gives an error. Here's what the org-mode tangle produces:
>

[ ... snip ... ]

Tangling is not meant to produce full LaTeX files.  If you want a full
and compilable LaTeX document, use the export functionality and export
to tex instead of pdf.  Then, you can manually compile the tex file.

Hope that helps,
Andreas