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Re: Why is importing the table into Mathematica so slow???

• To: mathgroup at smc.vnet.net
• Subject: [mg37908] Re: [mg37864] Why is importing the table into Mathematica so slow???
• From: Kirk Reinholtz <kirk.reinholtz at jpl.nasa.gov>
• Date: Tue, 19 Nov 2002 03:51:21 -0500 (EST)
• References: <200211150636.BAA16401@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

I've found it useful after the painful read to write the file in binary
format, and use that for subsequent sessions.  Takes a few seconds
instead of many minutes to read back that way.  I use DumpSave[].

Jia Guo wrote:
> 
> Hi,
> 
> I currently have such a problem in Mathematica:
> 
> I have a matrix of size 750*750. It is in a file and I will import the
> file to Mathematica using the command: g = Import ["matrix.dat",
> "Table"].
> 
> However, it took me over 2 hours to import and display the numbers in
> the notebook. But the transpose and reverse operations to the matrix
> are really fast: 4-5 seconds. I translated the matrix into a graph and
> when I was going to export it, the same problem happened. It slowed
> down again.
> 
> Does anybody know what should I do to avoid the big overhead?
> 
> Thank you!
> 
> Jia

• References:
  • Why is importing the table into Mathematica so slow???
    • From: jiaguo@uiuc.edu (Jia Guo)