[R] strange behavior of the compare operator

[Matthias Salvisberg]

I had a strange behavior of a function written a few days ago. I
pointed the problem down to the following minimal example.

can anyone explain why the following comparisons don't reply the
same"correct" answer?


Thanks for your reply!

Matthias




R version 3.1.1 (2014-07-10) -- "Sock it to Me"
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Platform: i386-w64-mingw32/i386 (32-bit)

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> sessionInfo()R version 3.1.1 (2014-07-10)
Platform: i386-w64-mingw32/i386 (32-bit)

locale:
[1] LC_COLLATE=German_Switzerland.1252
LC_CTYPE=German_Switzerland.1252
LC_MONETARY=German_Switzerland.1252 LC_NUMERIC=C
[5] LC_TIME=German_Switzerland.1252

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

loaded via a namespace (and not attached):
[1] tools_3.1.1> > rm(list = ls())> > myDataFrame <- data.frame(var1 =
seq(from = -1, to = 0, by = 0.01))> > any(myDataFrame$var1 ==
(0.68-1))[1] TRUE> > any(myDataFrame$var1 == -0.32)[1] FALSE> >
myDataFrame$var1[69][1] -0.32> > > str((0.68-1)) num -0.32> str(-0.32)
num -0.32> str(myDataFrame$var1) num [1:101] -1 -0.99 -0.98 -0.97
-0.96 -0.95 -0.94 -0.93 -0.92 -0.91 ...

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