Hello, I have a data set where there are multiple "cycles" per "patient," and I want to exclude from my data set instances where a variable was not measured every cycle. The difficulty is that the patients have different cycles; some have cycles 1,2, and 3, others only have 1 and 3 (and everything in between). Therefore, I'm having difficulty in in distinguishing between the NA of not having the cycle, and the NA of not having that particular measurement.
Here's a similar example of the data: Patient, Cycle, Variable1, Variable 2 A, 1, 4, 5 A, 2, 3, 3 A, 3, 4, NA B, 1, 6, 6 B, 2, NA, 6 C, 1, 6, 5 C, 3, 2, 2 So in this case, I would want all of Variable 1 for Patient B to be NA, and all of Variable 2 for Patient A to be NA. Does anyone have a good way of tackling this problem? I'm having issues with trying to subset the data such that I can compare Cycles within the patient's factor level. Thanks! [[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.