It's likely an infelicity of floating point representations (R FAQ 7.31) but admittedly, not a case I would have expected to present itself.
If you want it to work out as expected, try this: l <- 0.6 u <- seq(0.4, 0.7, 0.1) l.int <- (6L) / 10 u.int <- seq(4, 7) / 10 l < u l.int < u.int Michael On Thu, Feb 2, 2012 at 5:00 AM, Jonas Hal <j...@brf.dk> wrote: > The example here puzzles me. It seems like the < operator doesn't work as > expected. > >> l <- 0.6 >> u <- seq(0.4, 0.7, 0.1) >> u > [1] 0.4 0.5 0.6 0.7 >> mygrid <- expand.grid("l" = l, "u" = u) >> mygrid > l u > 1 0.6 0.4 > 2 0.6 0.5 > 3 0.6 0.6 > 4 0.6 0.7 >> mygridcollapsed <- mygrid[mygrid$l < mygrid$u, ] >> mygridcollapsed > l u > 3 0.6 0.6 > 4 0.6 0.7 > > In this little example I expect 'mygridcollapsed' only to return row 4 and > for it to return row 3 seems wrong. The strange thing is it seems to work if > I start the u-sequence at 0.5. > >> l <- 0.6 >> u <- seq(0.5, 0.7, 0.1) >> u > [1] 0.5 0.6 0.7 >> mygrid <- expand.grid("l" = l, "u" = u) >> mygrid > l u > 1 0.6 0.5 > 2 0.6 0.6 > 3 0.6 0.7 >> mygridcollapsed <- mygrid[mygrid$l < mygrid$u, ] >> mygridcollapsed > l u > 3 0.6 0.7 > > Maybe I'm missing something... > > Best wishes > Jonas Hal > > > _________________________________________________________________________________________________________________________________________ > BRFkredit sender e-mails og vedhaeftede dokumenter i ikke-krypteret form. > Hvis du ikke ?nsker at modtage oplysninger fra BRFkredit pr. e-mail, beder vi > dig meddele os det via brev eller e-mail. Denne e-mail kan indeholde > fortrolig information. Hvis du modtager e-mailen ved en fejl, beder vi dig > informere os om det hurtigst muligt. Samtidig beder vi dig slette e-mailen > uden at videresende eller kopiere indholdet. > _________________________________________________________________________________________________________________________________________ > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.