This is my result: > class(data) [1] "data.frame"
> str(data) 'data.frame': 2193 obs. of 83 variables: $ X.ID. : Factor w/ 2193 levels "'18201'",..: 1 2 3 4 5 6 7 8 9 10 ... $ X.kod. : Factor w/ 20 levels "'01'","'02'",..: 1 1 1 1 1 1 1 1 1 1 ... $ X.wiel. : int 7 7 7 7 7 7 7 8 8 8 ... $ X.piech. : num 1 99.9 4 0.5 4 2 99.9 2 2 99.9 ... $ X.rodz. : int NA 2 4 NA 4 2 2 3 2 NA ... David Winsemius wrote: > > > On Apr 19, 2009, at 6:45 PM, Grześ wrote: > >> >> I have database write as .csv file. > > The external sorage format is not likely to be relevant. What might be > informative would be to produce the code that reads this file. >> >> When I want to get sth from my database I get NULL, but I know that >> there is >> sth! >> For example: >> >>> data$ID >> NULL >>> data$kod >> NULL >> >> but command like below is always recognize by R >>> data[2,3] >> [1] '082' > > Tell is what happens when you enter: > > str(data) > class(data) > > Perhaps the third column is not named "ID" or "kod" or the object is > not a data.frame, but is rather a matrix. > > -- > David Winsemius >> >> >> In my opinion this problem is also connect with my attempt to create >> a tree. >> I always get errors. >> >>> t.tree0=rpart(ID~.,t.train) >> Error in eval(expr, envir, enclos) : object "ID" not found >> >>> t.tree0=rpart(kod~.,t.train) >> Error in eval(expr, envir, enclos) : object "kod" not found >> >> What I should do to create my simple trees? >> -- >> View this message in context: >> http://www.nabble.com/data%24ID--%3E-I-always-get-a-NULL-tp23128214p23128214.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. > > David Winsemius, MD > Heritage Laboratories > West Hartford, CT > > ______________________________________________ > 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. > > -- View this message in context: http://www.nabble.com/data%24ID--%3E-I-always-get-a-NULL-tp23128214p23132506.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.
