robert terwilliger raterwilgmailcom dear r help attempting make plot longitudinal data sample data frame shown id like show subjects plot set connecting line segments subject age would xaxis score would yaxis subject age score 1 10123 12 5106 2 10123 14 5000 3 10123 15 6222 4 10124 12 7442 5 10124 13 7273 6 10124 14 6341 7 10125 16 5455 8 10125 17 5000 9 10125 18 5435 10 10128 17 9783 11 10128 18 9787 12 10128 19 10000 help would appreciated regards robert terwilliger ______________________________________________ rhelprprojectorg mailing list httpsstatethzchmailmanlistinforhelp please read posting guide httpwwwrprojectorgpostingguidehtml provide commented minimal selfcontained reproducible code thu 07 aug 2008 180159 0400 r help longitudinal data plot