[R] Fwd: read-in, error???

[Sarah Goslee]

Hi Istvan,

Your OS and version of R (eg sessionInfo() ) would also be useful, as
would sending your reply to the R-help list and not just to me.

Sarah


---------- Forwarded message ----------
From: Istvan Nemeth <furgeurge at gmail.com>
Date: Fri, May 4, 2012 at 10:20 AM
Subject: Re: [R] read-in, error???
To: Sarah Goslee <sarah.goslee at gmail.com>


Dear Sarah,

Ctrl-C & Ctrl-V the data from the page to a txt file.
Then delete the unwanted "Data:" part

the code is:

LibPath <- getwd()
options(digits=20)

SmLs07 <- read.table(file.path(LibPath,"SmLs07.txt"),header=T,colClasses
= "numeric")
SmLs07$TrtF <- factor(SmLs07$Treatment)
lm02 <- lm(Response~TrtF,data=SmLs07)
anova(lm02)
summary(lm02)

I hope it helps to reproduce the phenomena.

Thanks,

István

2012/5/4 Sarah Goslee <sarah.goslee at gmail.com>
>
> Hi Istvan,
>
> That's most unusual, and quite unlikely (and much larger than the
> usual floating-point rounding errors).
>
> Please provide a reproducible example. I assume you got the data from here:
> http://www.itl.nist.gov/div898/strd/anova/SmLs07.dat
>
> What did you do with it then? How did you delete the header rows?
>
> What R code did you use to read it in?
>
> What OS and version of R are you working with?
>
> R has been well-validated; it's more likely that you did something
> sub-optimal while importing the data.
>
> Sarah
>
> On Fri, May 4, 2012 at 9:54 AM, Istvan Nemeth <furgeurge at gmail.com> wrote:
> > Dear Users!
> >
> > I encountered with some problem in data reading while I challenged R (and
> > me too) in a validation point of view.
> > In this issue, I tried to utilize some reference datasets (
> > http://www.itl.nist.gov/div898/strd/index.html).
> > And the result departed a bit from my expectations. This dataset dedicated
> > to challenge cancellation and accumulation errors (case SmLs07), that's why
> > this uncommon look of txt file.
> >
> > Treatment   Response
> >           1    1000000000000.4
> >           1    1000000000000.3
> >           1    1000000000000.5
> >           ......
> >           2    1000000000000.2
> >           2    1000000000000.4
> >           .....
> >           3    1000000000000.4
> >           3    1000000000000.6
> >           3    1000000000000.4
> >           .........
> > then after a read.table() I expect the same set instead I've got this:
> >
> >    Treatment              Response
> > 1           1 1000000000000.4000244
> > 2           1 1000000000000.3000488
> > 3           1 1000000000000.5000000
> > .........
> > 22          2 1000000000000.3000488
> > 23          2 1000000000000.1999512
> > 24          2 1000000000000.4000244
> > .......
> > 58          3 1000000000000.4000244
> > 59          3 1000000000000.5999756
> > 60          3 1000000000000.4000244
> > 61          3 1000000000000.5999756
> > 62          3 1000000000000.4000244
> > ......
> > a lots of number from the space. I assume that these numbers come from the
> > binary representation of such a tricky decimal numbers but my question is
> > how can I avoid this feature of the binary representation?
> >
> > Moreover, I wondered that it may raise some question in a regulated
> > environment.
> >
>
> --
> Sarah Goslee
> http://www.functionaldiversity.org




-- 
Sarah Goslee
http://www.stringpage.com
http://www.sarahgoslee.com
http://www.functionaldiversity.org