Re: [patch #5690] Clean up case code

[Ben Pfaff]

John Darrington <address@hidden> writes:

> On Tue, Jan 30, 2007 at 10:30:43PM -0800, Ben Pfaff wrote:
>
>      So I'm not proposing to
>      encourage use of random access where it's not necessary.
>      
> Would it therefore be worth having a flag passed to the casereader
> constructor which declares whether or not the casereader performs
> random access? 

What's the intended usage?

>      Probably the most powerful thing to stack on top of a casereader
>      is what I'm tentatively calling a "casegrouper".  A casegrouper
>      takes a casereader and a function that classifies consecutive
>      pairs of cases as in the same group or different groups.  It then
>      hands you a sequence of casereaders, one by one, each of which
>      contains a single group.  This is invaluable for SPLIT FILE, for
>      break groups on AGGREGATE or RANK or SORT CASES, and so on.
>      
> Sounds good.  I was thinking about looking at the percentiles code
> again.    (The more I look at it the less I like it.  Also, I'm not
> convinced that it gets the right answers in all cases.  It needs more
> test cases.)  But in view of the magnitude of the changes  you're
> making, I think I'll wait.  The new functions will probably make it
> simpler. 

If the new functions will make it simpler, OK.  Otherwise, please
go ahead and work on anything you like.  I'll merge into my tree
as needed.

>              * Write an extensive section for the manual describing
>                best practices for data processing under PSPP.  I'm
>                confident that, with this set of changes, PSPP data
>                processing will be mature enough that we can provide
>                good guidance for future developers this way.
>      
>                I might break this into a separate developers' guide,
>                along with the existing chapter on q2c.  What do you
>                think?
>
> I think a developers' guide is a good idea. q2c docs really don't
> belong in the user manual, so should be moved, along with the *.sav
> file format description.

OK, I was thinking about moving the .sav and .por descriptions
too, so you've just confirmed it for me.

>      data_model is a really really generic name.  It could be a name
>      for the model for any kind of data.  The name datasheet calls to
>      my mind a spreadsheet, which more specifically describes what the
>      datasheet actually implements.  So I'm not 100% happy with the
>      suggestion data_model.
>
> How about datasheetmodel or would that be too long?

It might work.
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