Dear list, I have 9 repeated measures (measurement variable == 'Delta13C') for individuals (ID variable == 'Individual_ID'. Each repeated measure is "indexed" (right term?) by the variable 'FeatherPosition' and given as c('P1', 'P2', 'P3', 'P4', 'P5', 'P6', 'P7', 'P8', 'P9'). I would like to calculate a correlation coefficient (r) and p.value for all measures of 'Delta13C' by individual. the function 'cor' only seems to work when comparing two individual measures (e.g. P1 and P2, P2 and P3, etc.) and only if I restructure my table. Any suggestions:
In SAS with 'proc corr' I would like results that look like: Individual ID, r, p WW_08I_01,-0.03,0.94 WW_08I_03,0.53,0.14 Trying to get started in R! Keith Sample dataset: WW_Sample_SI <- structure(list(Individual_ID = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L), .Label = c("WW_08I_01", "WW_08I_03"), class = "factor"), FeatherPosition = structure(c(1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L), .Label = c("P1", "P2", "P3", "P4", "P5", "P6", "P7", "P8", "P9"), class = "factor"), Delta13C = c(-18.3, -18.53, -19.55, -20.18, -20.96, -21.08, -21.5, -17.42, -13.18, -22.3, -22.2, -22.18, -22.14, -21.55, -20.85, -23.1, -20.75, -20.9)), .Names = c("Individual_ID", "FeatherPosition", "Delta13C"), class = "data.frame", row.names = c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16", "17", "18")) ******************************************************************************************* Keith Larson, PhD Student Evolutionary Ecology, Lund University Sölvegatan 37 223 62 Lund Sweden Phone: +46 (0)46 2229014 Mobile: +46 (0)73 0465016 Fax: +46 (0)46 2224716 Skype: sternacaspia FB: keith.w.lar...@gmail.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.