I need to count the trials in an experiment, separately for each subject. I thought about using the function "by" but I could not manage to achieve this. Instead, I tried "split" and I got closer to a solution but still not getting there yet. The following code should create a variable "miniblock" with the trial/miniblock number. split_cong=split(red_congruent,red_congruent$subject_nr) miniblock_cong=lapply(split_cong,seq_along) red_congruent$miniblock=unlist(miniblock_cong)
However, I get the following error message: Error in `$<-.data.frame`(`*tmp*`, "miniblock", value = c(1L, 2L, 3L, : replacement has 460 rows, data has 500 Is there a more efficient way to achieve the result? Maybe with "by" or dplyr? Thanks a lot in advance! ______________________________________________ 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.
