Re: Bigger array taking less memory than smaller array
- To: mathgroup at smc.vnet.net
- Subject: [mg27232] Re: Bigger array taking less memory than smaller array
- From: Albert Retey <albert.retey at visualanalysis.com>
- Date: Tue, 13 Feb 2001 03:35:40 -0500 (EST)
- Organization: Visual Analysis
- References: <9686h9$3ps@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Sebastien.deMentendeHorne at electrabel.com wrote:
>
> Hi,
>
> This example disturbs me...
>
> In[233]:=
> ByteCount[Array[0 &, {20, 10}]]
>
> Out[233]=
> 4424
>
> In[234]:=
> ByteCount[Array[0 &, {30, 10}]]
>
> Out[234]=
> 1260
>
> Some considerations about this ?
>
> Sébastien de Menten de Horne | ELECTRABEL
> Tel: ++32 10 48 51 76 | R&D Energy Markets,
> Fax: ++32 10 48 51 09 | Traverse d'Esope, 6
> Gsm: ++32 478 789 444 | B-1348 Louvain-la-Neuve, BELGIUM
Hi Sebastien,
There is a special way of organizing large Arrays of purely numerical
arrays in
Mathematica, called PackedArrays, you can learn a little about them in
the online help (AdditionalFunctions/DeveloperContext/Lists and
Matrices) although the documentation is not very extensive...
Developer`PackedArrayQ[Array[0 &, {20, 10}]]
False
Developer`PackedArrayQ[Array[0 &, {30, 10}]]
True
Albert
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