On Aug 5, 2014, at 10:20 AM, Spencer Graves wrote:
> What tools do you like for working with tab delimited text files up to
> 1.5 GB (under Windows 7 with 8 GB RAM)?
?data.table::fread
> Standard tools for smaller data sometimes grab all the available RAM,
> after which CPU usage drops to 3% ;-)
>
>
> The "bigmemory" project won the 2010 John Chambers Award but "is not
> available (for R version 3.1.0)".
>
>
> findFn("big data", 999) downloaded 961 links in 437 packages. That
> contains tools for data PostgreSQL and other formats, but I couldn't find
> anything for large tab delimited text files.
>
>
> Absent a better idea, I plan to write a function getField to extract a
> specific field from the data, then use that to split the data into 4 smaller
> files, which I think should be small enough that I can do what I want.
There is the colbycol package with which I have no experience, but I understand
it is designed to partition data into column sized objects.
#--- from its help file-----
cbc.get.col {colbycol} R Documentation
Reads a single column from the original file into memory
Description
Function cbc.read.table reads a file, stores it column by column in disk file
and creates a colbycol object. Functioncbc.get.col queries this object and
returns a single column.
> Thanks,
> Spencer
>
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David Winsemius
Alameda, CA, USA
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