From ggrothendieck at gmail.com  Thu Apr 17 20:35:48 2014
From: ggrothendieck at gmail.com (Gabor Grothendieck)
Date: Thu, 17 Apr 2014 14:35:48 -0400
Subject: [Rd] type.convert and doubles
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On Thu, Apr 17, 2014 at 2:21 PM, Murray Stokely <murray at stokely.org> wrote:
> If you later want to do arithmetic on them, you can choose to lose
> precision by using as.numeric() or use one of the large number
> packages on CRAN (GMP, int64, bit64, etc.).  But once you've dropped
> the precision with as.numeric you can never get it back, which is why
> the previous behavior was clearly dangerous.

Only if you knew that that column was supposed to be numeric. There is
nothing in type.convert or read.table to allow you to override how it
works (colClasses only works if you knew which columns are which in
the first place) nor is there anything to allow you to know which
columns were affected so that you know which columns to look at to fix
it yourself afterwards.



[Rd] type.convert and doubles
Gabor Grothendieck