[Numpy-discussion] Non-numerical info associated with sub-arrays

Perry Greenfield perry at stsci.edu
Sat Dec 28 11:03:35 CST 2002


> In fact, I'm thinking of adopting numarray for my pytables project, but I
> don't like the fact that data is not natively aligned inside
> recarrays, i.e.
> there is not a gap between the different fields even if datatypes doesn't
> match the "native" architecture alignement. IMO this can affect
> very much to
> the read/write efficency when one wants to work with data rows or
> columns of
> recarrays objects.
>
> Are there any plans to support this "natural" alignment in
> addition of the non-
> alignment schema present right now?.
>
Are you asking for an option to create record arrays with
aligned fields (in the sense that the addresses of all values
are consistent with their type)? Or are you arguing that
non-aligned columns must be prohibited? The former is certainly
possible (not not very difficult to implement; basically it requires
that record sizes must be a multiple of the largest numerical type,
and that padding is placed within records to ensure that all fields
have offsets that are a multiple of their size). We cannot accept
the latter since we need to access data that are stored in such
a non-aligned manner in data files.

> Francesc Alted

Thanks, Perry Greenfield






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