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Re: Import speed from different file types

  • To: mathgroup at smc.vnet.net
  • Subject: [mg118684] Re: Import speed from different file types
  • From: Bill Rowe <readnews at sbcglobal.net>
  • Date: Sat, 7 May 2011 07:32:26 -0400 (EDT)

On 5/4/11 at 7:47 PM, hisicon at gmail.com (CPE Bach) wrote:

>Hi users, So I have hundreds of data files of time series of stock
>returns. To make the import process as fast as possible in
>Mathematica 8, should I prepare those data files in what format?

>xls? csv? dat? txt?

Using xls format will be the slowest since Import has to do more
work to convert this into a Mathematica format. But while it is
easy to identify the slowest format, it isn't so easy to
identify the fastest format without knowing more about the data itself.

If you have mixed data types and will be using Import to read
the data then there will likely be little difference between csv
and txt. The dat extension isn't well defined. So, I cannot
predict performance. By not well defined, I mean different
programs will output data in different formats despite
consistently using the .dat file name extension.



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