[Plplot-devel] Re: simple PLPLOT interface for PDL

[Doug H. <dh...@uc...>]

Raphael:

> 
> However, I still think that the PP definition should be automaticaly
> generated from api.xml (it should be easy to modify my parsing scripts to do
> that), such that there will be a low level layer that will mimic the PLplot
> C API in Perl/PDL.  Then, as a second step, a OO layer can be written atop
> of that low level layer bindings.  Keeping things modular like that has the
> advantage that it will be easy to comply in the future to any generic plot
> API for PDL.

I'm already doing this (creating a low level interface that maps
directly to the plplot calls, and then putting a higher level interface
on top of it) but I'm working from a (slightly edited) version of
plplot.h instead of api.xml.

Is there a benefit to working from api.xml instead of the plplot.h?  All
things being equal, I'd rather work from the source instead of the
doc...

If there is a good reason to use api.xml, I would not mind adding the
XML parser as a dependency.

One thing more:  PP is a great tool for interfacing to PDL, but it has
one small limitation which makes the low level interface less useful to
call directly:  It handles non-PDL arguments (that is char, char * or
function pointers) in the so-called 'OtherPars' section.  This means
that when calling the perl version, the arguments get out of order, so

void c_plmtex(const char *side, PLFLT disp, PLFLT pos, PLFLT just, const
char *text);

becomes in perl:

plmtex($disp, $pos, $just, $side, $text);

(All the char * inputs are put last).

It is for this reason that I generally don't advertise the low level
routines and present users with only the high level versions.

Regards, 

  Doug Hunt

--

> 
> --
> Rafael

-- 
dh...@uc...
Software Engineer III, Sometimes Sysadmin
UCAR - COSMIC, Tel. (303) 497-2611