Hi Wang. I hope you are OK.
I'm stuck in the same problem. Did you find an answer for this question? Thanks in advance, Edgar -- View this message in context: http://r.789695.n4.nabble.com/HELP-FOR-COMPUTING-ENVIRONMENTAL-EFFICIENCY-INDEX-LUENBERGER-INDEX-tp4647883p4663437.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.
