I really appreciate to your attention. I want to change the data form "A" into "B"
http://r.789695.n4.nabble.com/file/n4428807/1.png http://r.789695.n4.nabble.com/file/n4428807/2.png In fact, there are 1095 column in data "A". Specifically, variable "publish_day" is when some book in the same row is published and "D-1", "D-2" means the term after the "publish day". Of course, the cells in data mean productivity in the day. What can be effecient way to do it? -- View this message in context: http://r.789695.n4.nabble.com/macro-function-tp4427385p4428807.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.