Here is a couple of very simple data.frames: X<-data.frame(A=1:10, B=0, C=1, Ob1=1:10, Ob2=2:11, Ob3=3:12, Ob4=4:13, Ob5=3:12, Ob6=2:11) Y<-data.frame(A=1:20, B=0, C=1, D=5, Ob1=1:10, Ob2=2:11, Ob3=3:12, Ob4=4:13, Ob5=3:12, Ob6=2:11, Ob7=5:9) Z<-data.frame(A=1:30, B=0, C=1, D=6, E=1:2, Ob1=1:10, Ob2=2:11, Ob3=3:12, Ob4=4:13, Ob5=3:12, Ob6=2:11, Ob7=1:10, Ob8=3:12)
Each row in the data.frame is a unique experiment. The fields Ob1:Ob6 (in the case of the first data.frame) represent observations taken at fixed intervals for specific that experiment. (Observation 1, Observation2, etc.) IMPORTANT - Different data files have different numbers of both experiments and observations as well as different observation rates. Some data.frames might have 50 observations/experiment at 10 minute intervals (a work day) while others might have 2000 observations/experiment at daily intervals representing years of data. The number of columns preceding OB1 varies from file to file but once I get to Ob1 I have set it up so that the names to the right are consecutive to the end of the row, so 2000 observations will have names Ob1:Ob2000. How could I use ReShape to create a generic new data.frame where all of the ObX columns become 'time' for the experiments in that data.frame? I.e. - Ob1:ObX become s single variable called time incrementing from 1:X. The generic answer cannot use any numbers like 1:3 or 4:12 because every file is different. I think I need to discover the dimensions of the data.frames and locations of Ob1 as well as the name of the last column, etc., to construct the right fields. We could (if it's legal in R) say things like Ob1:Ob11 but it doesn't seem legal. I do see I can say things like names(X[4]) to discover Ob1, and cute things like names(X[dim(X)[2]]) to get the last name, etc., but I cannot put it together how to use this to drive ReShape into making all the Observations into a single variable called time. I hope this is clear. Thanks, Mark ______________________________________________ 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.