On Oct 17, 2014, at 1:21 PM, Chichi Shu wrote: > Hi, R listers, > I¡¯m trying to compare a value of a row in a column to values of previous > rows in another column in a loop. ¡°i¡± is just from first row to the last > row. j is an another looping controller indicating the rows that row[i] will > be compared to and j will be rows before row[i]. I want to compare phone_1[i] > with phone_2[j] and vise versa. > for (i in 1: nrow(df)) { > if (df$Incremental[i] == 1) {mark[i] <- 1} > else {for (j in (i ¨C df$Incremental[i] + 1) : (i - 1)) { > if ((df$Phone_1[i] != "" & df$Phone_1[i] == df$Phone_2[j]) | > (df$Phone_2[i] != "" & df$Phone_2[i] == df$Phone_1[j])) { > mark[i] <- mark[j]} > else {mark[i] <- mark[i-1] + 1} > > } > } > However I¡¯m getting an error with phone_1[i] and phone_2[j], indicating that > ¡°level sets of factors are different¡±. I¡¯m not sure what I need to do to > fix it.
Factor fixing. An ancient, aRcane sport. Perhaps: lev2 <- unique( c( levels(phone_1), levels(phone_2) ) ) phone_1 <- factor(phone_1, levels=lev2) phone_2 <- factor(phone_2, levels=lev2) > Thanks! > [[alternative HTML version deleted]] And HTML posting is not well supported. Learn to post in that most ancient of computer tongues, plain text. > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. -- David Winsemius Alameda, CA, USA ______________________________________________ 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.