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Re: Reading data from large ascii-file

From: Francesco Potortì
Subject: Re: Reading data from large ascii-file
Date: Tue, 19 Apr 2011 13:17:41 +0200

>I am analyzing data from a 400MB ascii-file.  There are about 30 million
>data points in the file and the execution takes forever.
>Currently the program reads and processes the file element-by-element ( val
>= dlmread(fileName, "emptyvalue", [i, col, i, col]) ) and I suspect that
>this is a very unafficient way to do it.  Could you suggest a better

Reading one value at a time is the most inefficient way I can think of

First of all, are you sure you can't simply use load()?  Or use a trivial
conversion of your data so that you can use load()?

If your data is fixed, you should definitely consider the hint you were
already given: read the data once, then save it with 'save -binary':
when loading it with 'load' it should be as fast as possible.

Francesco Potortì (ricercatore)        Voice: +39 050 315 3058 (op.2111)
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