[R] writing lists fastly on file
Prof Brian Ripley
ripley at stats.ox.ac.uk
Thu Nov 30 14:42:27 CET 2006
On Thu, 30 Nov 2006, Duncan Murdoch wrote:
> On 11/30/2006 6:55 AM, Milton Cezar Ribeiro wrote:
>> Hi there,
>> I have a big amount of "lists" of data, each one with dimension
>> 1024x1024. When I save it in an ASCII file (using "write" function) it
>> take about 15 minutes. As I need run about 500,000 times this same
>> routine, and I would like to do this save task in a fast way.
>> In fact I will use these output files in another program that read
>> ASCII or RAW/Generic Binary (8bits) formats. Each value from my lists
>> ranges from 1 to 200 (integer values).
> I think this depends on the details. Can you show us what str() gives
> for one of these lists? Can you tell us how flexible the other program
> is about the format of what it needs to see? "RAW/Generic Binary"
> sounds like a format for an image from a digital camera; there might be
> packages available in R that are specifically designed to write that
> format but I don't know them.
Sounds like a job for writeBin(size=1).
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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