Re: SPV reader and writer support is now on master

[Ben Pfaff]

The work to support graphs is extensive. SPV files implement graphs
via ViZml, which is an elaborate language in itself. The "legacy tables"
that appear in older SPV files are actually ViZml themselves but they
use only a small subset of the language so one can ignore most of it,
but graphs don't seem to use a subset, they use the whole thing. So
to read and display graphs is equivalent to interpreting that language.

To write graphs to SPV might be simpler since one can just invent
appropriate templates, but once one has invested the effort to
implement ViZml--which is actually a nice, well-thought-out language
for visualization--it would make sense to use it inside PSPP instead
of just for input and output.

On Sun, Dec 29, 2019 at 2:03 AM John Darrington
<address@hidden> wrote:
>
> The tables seem to be much more aesthetically pleasing (but too small,
> as mentioned in another post).
>
> Does the work to support graphs require work only within the output
> system, or also within the graphing code itself?
>
> J'
>
> On Sat, Dec 28, 2019 at 11:02:57PM -0800, Ben Pfaff wrote:
>
>      I would appreciate experience reports, positive or negative.  The
>      main known limitation is that graphs are not yet supported (this
>      is actually a huge amount of work due to the way that SPSS
>      implements graphs).
>