Removing elements from a factor does not change the levels of the factor. ------------------------------------------------------------------------ ---- ir. Thierry Onkelinx Instituut voor natuur- en bosonderzoek team Biometrie & Kwaliteitszorg Gaverstraat 4 9500 Geraardsbergen Belgium
Research Institute for Nature and Forest team Biometrics & Quality Assurance Gaverstraat 4 9500 Geraardsbergen Belgium tel. + 32 54/436 185 thierry.onkel...@inbo.be www.inbo.be To call in the statistician after the experiment is done may be no more than asking him to perform a post-mortem examination: he may be able to say what the experiment died of. ~ Sir Ronald Aylmer Fisher The plural of anecdote is not data. ~ Roger Brinner The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from a given body of data. ~ John Tukey > -----Oorspronkelijk bericht----- > Van: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] Namens pdb > Verzonden: dinsdag 21 september 2010 13:42 > Aan: r-help@r-project.org > Onderwerp: [R] removed data is still there! > > > I'm confused, hope someone can point out what is not obvious to me. > > I thought I was creating a new data frame by 'deleting' rows > from an existing dataframe - I've tried 2 methods. > > But this new data frame seems to remember values from its > parent - even though there are no occurences. > > Where does it get the values versicolor and virginica from > and give then a count of 0? > > What am I missing? > > Thanks in advance. > > > summary(iris$Species) > setosa versicolor virginica > 50 50 50 > > > nrow(iris) > [1] 150 > > > iris1 <- iris[iris$Species == 'setosa',] > > > nrow(iris1) > [1] 50 > > > summary(iris1$Species) > setosa versicolor virginica > 50 0 0 > > boxplot(Petal.Width ~ Species, data = iris1, plot=1) > > > iris2 <- subset(iris, Species == 'setosa') > > > nrow(iris2) > [1] 50 > > > summary(iris2$Species) > setosa versicolor virginica > 50 0 0 > > > boxplot(Petal.Width ~ Species, data = iris2, plot=1) > > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/removed-data-is-still-there-tp25 > 48440p2548440.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. > Druk dit bericht a.u.b. niet onnodig af. Please do not print this message unnecessarily. Dit bericht en eventuele bijlagen geven enkel de visie van de schrijver weer en binden het INBO onder geen enkel beding, zolang dit bericht niet bevestigd is door een geldig ondertekend document. The views expressed in this message and any annex are purely those of the writer and may not be regarded as stating an official position of INBO, as long as the message is not confirmed by a duly signed document. ______________________________________________ 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.
