[R] R not 'seeing' numbers?!

[R. Michael Weylandt]

R FAQ 7.31 strikes again.

:-)

Michael

tmp[3105] == 35.52
[1] FALSE
 tmp[3105] - 35.52
[1] -7.105427e-15

all.equal(tmp[3105], 35.52)
TRUE

On Wed, Nov 16, 2011 at 10:42 AM, oscar <ob266 at cam.ac.uk> wrote:
> Hello.
>
> I recently came across the extremely strange problem (see below) of R
> telling me that elements of a list do not exist...
>
> I have tried running this small script on 2 computers (Mac OSX 10.7 &
> Windows 7) running the latest releases or R (2.13.2 on Mac, 2.14.0 on Win).
> I have tried it both in the standard R console, and in RStudio (v.
> 0.94.110), and all have the same problem.
>
> Any ideas?!  I'm stumped...
>
> Thanks,
>
> Oscar.
>
> Code (with comments):
>
>
> tmp=seq(20,90,0.005)
>
> # I want to find the position of 35.52:
> which(tmp==35.52)
> # integer(0)  -- It's not there?!
>
> tmp[3100:3110] # check to see if it's there...
> # [1] 35.495 35.500 35.505 35.510 35.515 35.520 35.525 35.530 35.535 35.540
> 35.545  -- it is.
> which(tmp==35.525)
> # [1] 3106
> which(tmp==35.515)
> # [1] 3104
> tmp[3105]
> # [1] 35.52
>
> # Interestingly:
> for (i in seq(30.52,50.52,1)) print(paste(i,which(tmp==i))) # works fine...
> # ... I'm stuck.
>
>
>
> --
> View this message in context: http://r.789695.n4.nabble.com/R-not-seeing-numbers-tp4076766p4076766.html
> Sent from the R help mailing list archive at Nabble.com.
>
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