On Jul 2, 2009, at 9:58 PM, Tom Marsh wrote:
>
> > I suppose the question I have is what does your "ndf" object
> contain?
> > Is it a copy of all the metadata from the file is it still
> attached to
> > the file (it's the equivalent of asking whether this is like the
> > PDL::IO::NDF perl module that reads everything in to memory and
> closes
> > the file,
>
> yes, it is basically this. It would run out of memory on very large
> files
> for instance.
>
> > compared to the perl NDF interface that returns back the NDF
> > identifier (ie the NDF object in reality) and lets you do methods on
> > the open file just like you would be using the C or fortran
> interface.
>
> but I take it that this second version that you recommend?
They are different. It all depends on what your market is. My "market"
was to give me full access to NDFs and HDS structures from perl.
The PDL approach is fine. Just because I started by wrapping the core
NDF library and then built up the PDL reader using the perl wrapper
does not mean that that is how it needs to be done in python.
--
Tim Jenness
Joint Astronomy Centre
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