Re: [Pytables-users] Storing simulation data

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

Hi Dragan,

I see. Well, the sort answer is no: PyTables does not support
multidimensional arrays of tables. HDF5 does support this as well as
numarray. We can start thinking in implementing such a support
sometime after PyTables 1.0 release.

However, depending on what you are trying to do, you may want to check
VLArrays of objects. You can create a numarray.RecArray object for
each simulation run and save it as an entry in a VLArray.

Regards,

A Dilluns 25 Abril 2005 13:12, v=E0reu escriure:
> Hello Francesc,
>
> I think I was not clear enough. My question was
> related to having an multidimensional array of tables.
> Each element of the array would therefore present one
> table with data of one simulation run.
> Does this make any sence to you?
>
> Thanks for replying.
>
> Greetings, Dragan.
>
> --- Francesc Altet <fa...@ca...> wrote:
> > Hello Dragan,
> >
> > On Sunday 24 April 2005 17:59, dragan savic wrote:
> > > A table is typically the result of a simulation
> >
> > run.
> >
> > > When more runs are done, each run has normally
> > > different values for one of parameters. In my case
> >
> > I
> >
> > > have for example three parameters: switch size,
> >
> > buffer
> >
> > > size and load. I would like to have tables as
> >
> > elements
> >
> > > of an N dimensional array, where each parameter
> > > represents a different dimension, and the number
> >
> > of
> >
> > > possible values of that parameter is the size of
> >
> > the
> >
> > > array along that dimension.  Each dimension should
> > > have a scalar or a string type.
> > > Is this possible to achieve with Pytables?
> >
> > Well, if I have not misunderstood you, yes, I think
> > you can achieve
> > this goal using PyTables. Just declare the next
> > description
> > dictionary:
> >
> > tsim=3D{'switch_size':
> > UInt16Col(shape=3Dmax_size_switch),
> >       'buffer_size':
> > UInt32Col(shape=3Dmax_buffer_switch),
> >       'load': UInt8Col(shape=3Dmax_size_load),
> >      }
> >
> > Then, create the table with compression enabled:
> >
> > table =3D fileh.createTable(group, 'table', tsim, "A
> > table", Filters(1))
> >
> > Please, take in account that, as you use compression
> > (see the
> > Filters(1) parameter), you don't waste too much
> > space by booking
> > columns with maximum possible sizes.
> >
> > If you want true variable length records, even with
> > compression
> > support (but not able to deal with heterogeneous
> > data), you can use a
> > combination of three VLArray objects (one per each
> > parameter). See
>
> http://pytables.sourceforge.net/html/tut/vlarray2.html
>
> > for an example
> > of use.
> >
> > HTH,
> >
> > Francesc Altet
>
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=2D-=20
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