Hi Xiyan, I have to admit that your puzzle very nearly stumped me. At first I thought the question was:
"What are the numbers of rows with changed and unchanged class values?" That doesn't work as there are at most four rows and your answer sums to five. I then tried: "How many times does at least one value of class change between successive data frames?" Nope, four have at least one change. Could it have been: "Using unique combinations of the values of Netto and Bruto, how many changes have occurred?" Wrong again, there are 12 combinations, not five. Surely you don't mean: "In how many data frames does ta least one value of class equal 'no'?" df1<-data.frame(Netto=c(10,100),Bruto=c(1000,20),class=c("yes","yes")) df2<-data.frame(Netto=c(101,100),Bruto=c(1000,210),class=c("yes","no")) df3<-data.frame(Netto=c(10,12,100),Bruto=c(10,28,20),class=c("yes","yes","yes")) df4<-data.frame(Netto=c(120,400),Bruto=c(200,20),class=c("no","yes")) df5<-data.frame(Netto=c(110,1100,120,1140),Bruto=c(12000,120,100,125), class=c("yes","yes","yes","yes")) sxdat<-list(df1,df2,df3,df4,df5) table(ifelse(unlist(lapply(sxdat,function(x) return(any(x$class=="no")))),"changed","unchanged")) Jim On Wed, May 20, 2015 at 1:04 PM, Bert Gunter <gunter.ber...@gene.com> wrote: > Probably "or what." > > This demonstrates a fundamental conundrum: many users or prospective users > of R have had little exposure to data structures in their formal education > and therefore can be flummoxed by R's fussiness -- as any programming > language must necessarily be. Consider: data frames, matrices, lists, > "classes", objects with attributes (e.g. factors),... > > Excel, which is basically structureless, of course, exacerbates the > problem. Those accustomed to its tolerance (and the confusion that results) > expect R to behave the same way. Education is the only recourse, either in > formal courses or through R tutorials that strongly emphasize this aspect > of interacting with R and especially writing effective code. But that > demands effort and, to some extent, aptitude... both of which seem to be in > increasingly short supply amidst the worldwide explosion in R's usage. > > Of course, feel free to disagree... Just my $.02 > > Cheers, > Bert > > > Bert Gunter > Genentech Nonclinical Biostatistics > (650) 467-7374 > > "Data is not information. Information is not knowledge. And knowledge is > certainly not wisdom." > Clifford Stoll > > > > On Tue, May 19, 2015 at 7:02 PM, John Kane <jrkrid...@inbox.com> wrote: > >> Is this a list of data.frames or what? >> >> Please have a look at one or both of these for some ideas of how to ask a >> question and provide information on the problem. The better you can >> describe what you have and what you need the better people can help. >> >> http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example >> and http://adv-r.had.co.nz/Reproducibility.html >> >> >> John Kane >> Kingston ON Canada >> >> >> > -----Original Message----- >> > From: soe.xi...@gmail.com >> > Sent: Tue, 19 May 2015 23:37:13 +0700 >> > To: r-help@r-project.org >> > Subject: [R] Count unchanged class attribute >> > >> > Maybe someone can help me. >> > Suppose I have data-set like this: >> > >> > Netto Bruto class >> > 1 10 1000 yes >> > 2 100 20 yes >> > >> > >> > Netto Bruto class >> > 1 101 1000 yes >> > 2 100 210 no >> > >> > >> > Netto Bruto class >> > 1 10 10 yes >> > 2 12 28 yes >> > 3 100 20 yes >> > >> > Netto Bruto class >> > 1 120 200 no >> > 2 400 20 yes >> > >> > >> > Netto Bruto class >> > 1 110 12000 yes >> > 2 1100 120 yes >> > 3 120 100 yes >> > 4 1140 125 yes >> > >> > How to calculate the number of classes has changed. >> > The expected result is >> > - class changed 2 >> > - class unchanged 3 >> > >> > >> > Thank you so much. >> > Soe Xiyan >> > >> > [[alternative HTML version deleted]] >> > >> > ______________________________________________ >> > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >> > 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. >> >> ____________________________________________________________ >> Can't remember your password? Do you need a strong and secure password? >> Use Password manager! It stores your passwords & protects your account. >> >> ______________________________________________ >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >> 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. >> > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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 -- To UNSUBSCRIBE and more, see 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.