Hello All. I am running R 2.0.0 with a Win XP operating system. The same problem occured with R 1.9.1 but not with R.1.3.1 on a Win NT computer.
My request is about the following problem with the sort function: The vector price is a vector of 789 asset prices of the following form, > mode(price) [1] "numeric" > price[1:10] [1] 1.1315 1.1314 1.1313 1.1314 1.1315 1.1316 1.1315 1.1317 [9] 1.1316 1.1316 Then the returns are defined to be the differences, > ret <- diff(price) > ret[1:10] [1] -1e-04 -1e-04 1e-04 1e-04 1e-04 -1e-04 2e-04 -1e-04 [9] 0e+00 0e+00 Here R recognizes the first two entries and also the second ones to be equal (I did not found any two equal entries, where R didnt recognized this relation), > ret[1]==ret[2] [1] TRUE > ret[3]==ret[4] [1] TRUE But after sorting the vector, this ist not longer true, > s <- sort(ret) > s[1:10] [1] -5e-04 -5e-04 -5e-04 -5e-04 -5e-04 -4e-04 -4e-04 -4e-04 [9] -4e-04 -4e-04 > s[1]==s[2] [1] FALSE Taking the difference of the first two entries yields > s[1]-s[2] [1] -2.220446e-16 which seems to be a numerical artefact. Is this a bug, or just a handling error by me? Thanks a lot for your answers, Kay Frederik Pilz Ruhr-Universitaet Bochum Germany [EMAIL PROTECTED] ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
