Hi, This is the input data frame:
############################################### df.1 = read.table(header=T,text=" id gender WMC_alcohol WMC_caffeine WMC_no.drug RT_alcohol RT_caffeine RT_no.drug 1 1 female 3.7 3.7 3.9 488 236 371 2 2 female 6.4 7.3 7.9 607 376 349 3 3 female 4.6 7.4 7.3 643 226 412 4 4 male 6.4 7.8 8.2 684 206 252 5 5 female 4.9 5.2 7.0 593 262 439 6 6 male 5.4 6.6 7.2 492 230 464 7 7 male 7.9 7.9 8.9 690 259 327 8 8 male 4.1 5.9 4.5 486 230 305 9 9 female 5.2 6.2 7.2 686 273 327 10 10 female 6.2 7.4 7.8 645 240 498 ") ############################################### This is the desired output: ############################################### id gender drug WMC RT 1 1 female alcohol 3.7 488 2 2 female alcohol 6.4 607 3 3 female alcohol 4.6 643 4 4 male alcohol 6.4 684 5 5 female alcohol 4.9 593 6 6 male alcohol 5.4 492 7 7 male alcohol 7.9 690 8 8 male alcohol 4.1 486 9 9 female alcohol 5.2 686 10 10 female alcohol 6.2 645 11 1 female caffeine 3.7 236 12 2 female caffeine 7.3 376 ############################################### I know some melt and cast magic is required. But I was unable to sort it myself. Here are the dput versions: Input Data Frame ############################################### > dput(df.1) structure(list(id = 1:10, gender = structure(c(1L, 1L, 1L, 2L, 1L, 2L, 2L, 2L, 1L, 1L), .Label = c("female", "male"), class = "factor"), WMC_alcohol = c(3.7, 6.4, 4.6, 6.4, 4.9, 5.4, 7.9, 4.1, 5.2, 6.2), WMC_caffeine = c(3.7, 7.3, 7.4, 7.8, 5.2, 6.6, 7.9, 5.9, 6.2, 7.4), WMC_no.drug = c(3.9, 7.9, 7.3, 8.2, 7, 7.2, 8.9, 4.5, 7.2, 7.8), RT_alcohol = c(488L, 607L, 643L, 684L, 593L, 492L, 690L, 486L, 686L, 645L), RT_caffeine = c(236L, 376L, 226L, 206L, 262L, 230L, 259L, 230L, 273L, 240L), RT_no.drug = c(371L, 349L, 412L, 252L, 439L, 464L, 327L, 305L, 327L, 498L)), .Names = c("id", "gender", "WMC_alcohol", "WMC_caffeine", "WMC_no.drug", "RT_alcohol", "RT_caffeine", "RT_no.drug"), class = "data.frame", row.names = c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10")) Output Data Frame ############################################### > dput(df.output) structure(list(id = c(1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 1L, 2L), gender = structure(c(1L, 1L, 1L, 2L, 1L, 2L, 2L, 2L, 1L, 1L, 1L, 1L), .Label = c("female", "male"), class = "factor"), drug = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L), .Label = c("alcohol", "caffeine"), class = "factor"), WMC = c(3.7, 6.4, 4.6, 6.4, 4.9, 5.4, 7.9, 4.1, 5.2, 6.2, 3.7, 7.3), RT = c(488L, 607L, 643L, 684L, 593L, 492L, 690L, 486L, 686L, 645L, 236L, 376L)), .Names = c("id", "gender", "drug", "WMC", "RT"), class = "data.frame", row.names = c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12")) Cheers ! [[alternative HTML version deleted]] ______________________________________________ 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.