Hello I hope that there is a simple solution to this apparently complex problem. Any help will be much appreciated: I have a dataframe with Left and Right readings (that is, elements in each row are paired). For instance, Left Right [1] 9 8 [2] 4 3 [3] 2 1 [4] 6 5 [5] 3 1 [6] 4 1 [7] 3 2 [8] 4 2 [9] 10 8 [10] 9 10 I need to produce a new data frame where the values are transformed according to a look-up table such as input output [1] 5 1 [2] 10 1 [3] 4 2 [4] 8 3 [5] 6 5 [6] 5 6 [7] 7 6 [8] 2 7 [9] 9 7 [10] 10 7 [11] 2 8 So [1, ] in the new dataframe would be 7 3. Quite simple so far, but what makes things complicated is the multiple outputs for a single input. In this example, 10 corresponds to 1 and 7 so [9, ] in the input dataframe must yield two rows in its output counterpart: 1 3 and 7 3. Likewise the output for [10, ] should be 7 1 and 7 7. In addition, given that 3 and 1 are missing as inputs the output for [5, ] should be NA NA. Thank you very much for your time. Juan Antonio Balbuena
-- Dr. Juan A. Balbuena Marine Zoology Unit Cavanilles Institute of Biodiversity and Evolutionary Biology University of Valencia [1]http://www.uv.es/~balbuena P.O. Box 22085 [2]http://www.uv.es/cavanilles/zoomarin/index.htm 46071 Valencia, Spain [3]http://cetus.uv.es/mullpardb/index.html e-mail: [4]j.a.balbu...@uv.es tel. +34 963 543 658 fax +34 963 543 733 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ NOTE! For shipments by EXPRESS COURIER use the following street address: C/ Catedrático José Beltrán 2, 46980 Paterna (Valencia), Spain. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ References 1. http://www.uv.es/%7Ebalbuena 2. http://www.uv.es/cavanilles/zoomarin/index.htm 3. http://cetus.uv.es/mullpardb/index.html 4. mailto:j.a.balbu...@uv.es ______________________________________________ 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.