Thank for your help, and sorry for posting before reading the FAQ, I know
it is one of the basic rules. Though, knowing myself I would never relate
the error in rep with 0.29*100!=29
2013/4/9 arun
> Possibly R FAQ 7.31
>
> length(rep(TRUE,signif(0.29*100,2)))
> #[1] 29
> A.K.
>
>
> ----- Original Message -----
> From: Jorge Fernando Saraiva de Menezes
> To: r-help@r-project.org
> Cc:
> Sent: Tuesday, April 9, 2013 12:11 PM
> Subject: [R] rep() fails at times=0.29*100
>
> Dear list,
>
> I have found an unusual behavior and would like to check if it is a
> possible bug, and if updating R would fix it. I am not sure if should post
> it in this mail list but I don't where is R bug tracker. The only mention I
> found that might relate to this is "If times is a computed quantity it is
> prudent to add a small fuzz." in rep() help, but not sure if it is related
> to this particular problem
>
> Here it goes:
>
> > rep(TRUE,29)
> [1] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE
> TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE
> [28] TRUE TRUE
> > rep(TRUE,0.29*100)
> [1] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE
> TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE
> [28] TRUE
> > length(rep(TRUE,29))
> [1] 29
> > length(rep(TRUE,0.29*100))
> [1] 28
>
> Just to make sure:
> > 0.29*100
> [1] 29
>
> This behavior seems to be independent of what is being repeated (rep()'s
> first argument)
> > length(rep(1,0.29*100))
> [1] 28
>
> Also it occurs only with the 0.29.
> > length(rep(1,0.291*100))
> [1] 29
> > for(a in seq(0,1,0.01)) {print(sum(rep(TRUE,a*100)))} #also shows correct
> values in values from 0 to 1 except for 0.29.
>
> I have confirmed that this behavior happens in more than one machine
> (though I only have session info of this one)
>
>
> > sessionInfo()
> R version 2.15.3 (2013-03-01)
> Platform: x86_64-w64-mingw32/x64 (64-bit)
>
> locale:
> [1] LC_COLLATE=Portuguese_Brazil.1252 LC_CTYPE=Portuguese_Brazil.1252
> LC_MONETARY=Portuguese_Brazil.1252
> [4] LC_NUMERIC=C LC_TIME=Portuguese_Brazil.1252
>
> attached base packages:
> [1] stats graphics grDevices utils datasets methods base
>
> other attached packages:
> [1] spatstat_1.31-1 deldir_0.0-21 mgcv_1.7-22
>
> loaded via a namespace (and not attached):
> [1] grid_2.15.3 lattice_0.20-13 Matrix_1.0-11 nlme_3.1-108
> tools_2.15.3
>
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>
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> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
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>
>
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