Thanks everyone. I tried them all, and got all to work except for the last one.
I tried > sort2v4$adj_mean<-within(sort2v4, ave(mean, point, FUN=function(x)x-x[1])) > head(sort2v4) point time mean sd adj_mean.point adj_mean.time adj_mean.mean adj_mean.sd 1 1 1 52.50100 1.5073927 1 1 52.50100 1.5073927 3 1 2 54.50182 0.8510329 1 2 54.50182 0.8510329 4 1 3 56.60174 1.5787222 1 3 56.60174 1.5787222 5 1 4 57.20000 1.2292726 1 4 57.20000 1.2292726 6 1 5 59.30000 2.2632327 1 5 59.30000 2.2632327 7 1 6 57.80089 1.4745218 1 6 57.80089 1.4745218 but am getting the columns in duplicate, rather than it performing the function. Any advice? Thanks again, Kristiina -- View this message in context: http://r.789695.n4.nabble.com/How-to-adjust-the-start-of-a-series-to-zero-i-e-subtract-the-first-value-from-the-sequence-tp4634999p4635062.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.
