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MathGroup Archive 2000

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Re: Saving Large Matrices

  • To: mathgroup at smc.vnet.net
  • Subject: [mg24801] Re: Saving Large Matrices
  • From: "P.J. Hinton" <paulh at wolfram.com>
  • Date: Sun, 13 Aug 2000 03:16:40 -0400 (EDT)
  • Organization: Wolfram Research, Inc.
  • References: <8mtbui$7pi@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

On 10 Aug 2000 bbongiorno at attglobal.net wrote:

> I need a effective way to store and retrieve a 300,000 x 44 matrix that
> includes alpha numeric and numeric cells.
> 
> The data is first downloaded from a database into a mathematica variable
> in a note book. Included in some of the alpha numeric cells are commas,
> tabs and spaces and therefore I cannot use Write function. If I use the
> Write function to store the matrix, the integrity of the shape of the
> matrix is impaired.
> 
> The Export function  works but it takes 24 hours to store the matrix on
> a Pentium II 300 with major virtual memory usage.

You don't say whether or not you need to make this data file available to
other applications.  If your are just trying to store it in a format that
will be readable by the kernel, you may want to consider using the
DumpSave[] function.  This stores the expression in a binary format that
can be read very quickly back into the kernel.

-- 
P.J. Hinton
User Interface Programmer                         paulh at wolfram.com
Wolfram Research, Inc.
Disclaimer: Opinions expressed herein are those of the author alone.


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