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Re: Packed array and ReadList

  • To: mathgroup at smc.vnet.net
  • Subject: [mg41500] Re: Packed array and ReadList
  • From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
  • Date: Fri, 23 May 2003 03:24:53 -0400 (EDT)
  • Organization: Universitaet Leipzig
  • References: <baib30$dm3$1@smc.vnet.net>
  • Reply-to: kuska at informatik.uni-leipzig.de
  • Sender: owner-wri-mathgroup at wolfram.com

Hi,

MathLink typical send the data to the Kernel as a packed
array the the kernel won't unpack it.

So you should write a MathLink program ...

Regards
  Jens

"Bruyndonckx P." wrote:
> 
> I have a very large text file with real numbers.  I would like to read this numbers and store them in a packed array.
> My computer has sufficient memory to store all numbers in a packed array form.  However, when I try something like
> ToPackedArray[Readlist[filename,Real]], Mathematica uses much more memory during the process.  Hence I assume the
> numbers are first stored in a normal list and the packed.
> 
> Is there a way to read a file of numbers directly into a packed array ? Since I am specifying that file file just
> contains numbers, I expected that Mathematica (4.2) would store the result of the ReadList commando in a packed array
> without me telling it to do so.  But it doesn't (PackedArrayQ gives false) and I have to add the ToPackedArray
> commando myself.
> 
> Peter


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