Re: [Pytables-users] Indexing Arrays: a la numarray

[Francesc A. <fa...@ca...>]

Hi Travlr,

A Wednesday 07 September 2005 09:32, travlr va escriure:
> Today, I went back and got the "selecting and getting" Table <rows> and
> Column <elements> for versions 1.0 and 1.1 working again, The attachments
> provided are a tables.Table.dif file for each version.
> Below is an example of it's usage.

Thanks for the patches. I think is a good idea to allow retrieving
values using an index array. I'll apply the patches and hopefully they
will appear in the forthcoming PyTables 1.2.

> Also Fransesc, two questions:
> 1) Could the tables.Table.Column also have an .nrows (nelements) attribut=
e?

Well, you have access to the table object via the .table attribute. So
you can use columnObject.table.nrows.

> 2) Once bounded, tables.Table used to return as a <class
> 'numarray.records.RecArray'> object. Now it returns a <class
> 'tables.nestedrecords.NestedRecArray'> object....Is this necessary?.

Strictly speaking no, but from PyTables 1.1 on, Table objects supports
nested fields, so we have been forced to introduce such a
NestedRecArray object. This is by not means a brand new object, but it
is strongly based on RecArray (in fact, it inherits from RecArray).
If, for whatever reason, you prefer a RecArray object, you have a
couple of possibilities:

1.- Use asRecArray() method. See:
http://pytables.sourceforge.net/html-doc/usersguide8.html#sectionB.2
for more details.

2.- If your table has not nested fields, your NestedRecArray will be
flat, and you can access the underlying RecArray object by just
getting the object pointed by the ._flatArray attribute.

Cheers,

=2D-=20
>0,0<   Francesc Altet =A0 =A0 http://www.carabos.com/
V   V   C=E1rabos Coop. V. =A0=A0Enjoy Data
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