[R] big data?

[David Winsemius]

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