graphviz dot block export and evaluate

graphviz dot block export and evaluate

[Dmitri Makarov]

Hi all,

Has anyone successfully exported and evaluated src blocks with graphviz dot code?
I'm trying to export this block

   #+BEGIN_SRC dot :export both
     digraph G {
       A -> B
     }
   #+END_SRC

and I'm getting the error

org-babel-exp processing...
executing Dot code block...
file-name-extension: Wrong type argument: stringp, nil

How do you debug such problems?

Regards,

Dmitri

Re: graphviz dot block export and evaluate

[Bastien]

Hi Dmitri,

Dmitri Makarov <dmakarv@gmail.com> writes:

>    #+BEGIN_SRC dot :export both
>      digraph G {
>        A -> B
>      }
>    #+END_SRC

You need a :file parameter:

#+BEGIN_SRC dot :file test.png :export both
digraph G {
  A -> B
}
#+END_SRC

HTH,

-- 
 Bastien

Re: graphviz dot block export and evaluate

[Thomas S. Dye]

Dmitri Makarov <dmakarv@gmail.com> writes:

> Hi all,
>
> Has anyone successfully exported and evaluated src blocks with
> graphviz dot code?
> I'm trying to export this block
>
>    #+BEGIN_SRC dot :export both
>      digraph G {
>        A -> B
>      }
>    #+END_SRC
>
> and I'm getting the error
>
> org-babel-exp processing...
> executing Dot code block...
> file-name-extension: Wrong type argument: stringp, nil
>
> How do you debug such problems?
>
> Regards,
>
> Dmitri

Aloha Dmitri,

Currently, you can debug such problems by looking at the source code of
ob-dot.el.  Or, by asking the list, as you did.

Your example is lacking a :file header argument.  dot source code blocks
produce graphics files and babel leaves it to the user to name the
output file.  The file-name-extension function is looking for the value
of the :file header argument, so that it can configure the call to dot.
It is expecting to see a string, but gets nil because the header
argument is absent.

Also, the correct keyword is :exports, with a final "s".

You can find an example of dot code use here:
http://www.jstatsoft.org/v46/i03

hth,
Tom
-- 
Thomas S. Dye
http://www.tsdye.com

Re: graphviz dot block export and evaluate

[Dmitri Makarov]

Hi Tom and Bastien,

Thank you, your answers helped a lot.
My fault that I used "export" not "exports" and that I didn't read the section Specific header arguments in the Org manual.

Thanks!

Dmitri

On Sep 28, 2012, at 7:14 PM, tsd@tsdye.com (Thomas S. Dye) wrote:

> Dmitri Makarov <dmakarv@gmail.com> writes:
> 
>> Hi all,
>> 
>> Has anyone successfully exported and evaluated src blocks with
>> graphviz dot code?
>> I'm trying to export this block
>> 
>>   #+BEGIN_SRC dot :export both
>>     digraph G {
>>       A -> B
>>     }
>>   #+END_SRC
>> 
>> and I'm getting the error
>> 
>> org-babel-exp processing...
>> executing Dot code block...
>> file-name-extension: Wrong type argument: stringp, nil
>> 
>> How do you debug such problems?
>> 
>> Regards,
>> 
>> Dmitri
> 
> Aloha Dmitri,
> 
> Currently, you can debug such problems by looking at the source code of
> ob-dot.el.  Or, by asking the list, as you did.
> 
> Your example is lacking a :file header argument.  dot source code blocks
> produce graphics files and babel leaves it to the user to name the
> output file.  The file-name-extension function is looking for the value
> of the :file header argument, so that it can configure the call to dot.
> It is expecting to see a string, but gets nil because the header
> argument is absent.
> 
> Also, the correct keyword is :exports, with a final "s".
> 
> You can find an example of dot code use here:
> http://www.jstatsoft.org/v46/i03
> 
> hth,
> Tom
> -- 
> Thomas S. Dye
> http://www.tsdye.com