Hi, May be this helps: fun1 <- function(dat){ lst1 <- lapply(split(dat,dat$ID),function(y){ rl <- rle(y$x) data.frame(ID=unique(y$ID),MAXZero=max(rl$lengths[rl$values==0])) }) do.call(rbind,lst1) }
fun1(df) # ID MAXZero #1 1 2 #2 2 2 #3 3 1 A.K. On Thursday, October 31, 2013 7:22 AM, Carlos Nasher <carlos.nas...@googlemail.com> wrote: Dear R-helpers, I need to count the maximum number of consecutive zero values of a variable in a dataframe by different groups. My dataframe looks like this: ID <- c(1,1,1,2,2,3,3,3,3) x <- c(1,0,0,0,0,1,1,0,1) df <- data.frame(ID=ID,x=x) rm(ID,x) So I want to get the max number of consecutive zeros of variable x for each ID. I found rle() to be helpful for this task; so I did: FUN <- function(x) { rles <- rle(x == 0) } consec <- lapply(split(df[,2],df[,1]), FUN) consec is now an rle object containing lists für each ID that contain $lenghts: int as the counts for every consecutive number and $values: logi indicating if the consecutive numbers are zero or not. Unfortunately I'm not very experienced with lists. Could you help me how to extract the max number of consec zeros for each ID and return the result as a dataframe containing ID and max number of consecutive zeros? Different approaches are also welcome. Since the real dataframe is quite large, a fast solution is appreciated. Best regards, Carlos -- ----------------------------------------------------------------- Carlos Nasher Buchenstr. 12 22299 Hamburg tel: +49 (0)40 67952962 mobil: +49 (0)175 9386725 mail: carlos.nas...@gmail.com [[alternative HTML version deleted]] ______________________________________________ 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. ______________________________________________ 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.