Dear all, I have received some data on birds that looks sth like this:
# a unique id for each individual id <- c(1,1,1,2,2,2,3,3,3,4,4,5,6) # the year the bird was measured year <- c(1995, 1996, 1997, 1995, 1996, 1997, 1996, 1997, 1998, 1996, 1997, 1997, 1998) # the year the bird was hatched year.hatch <- c(1995, 1995, 1995, 1995, 1995, 1995, 1996, 1996, 1996, 1996, 1996, 1997, 1998) # the year when the bird reproduced the first time (for simplicity in the dummy data, all birds reproduce the year after it was born) year.1st.reprod <- year.hatch + 1 # some status (0/1) of an individual status <- c(1, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 0, 1) # the id of the mother id.mother <- c(NA, NA, NA, NA, NA, NA, 1, 1, 1, 2, 2, 3, 3) # Status of the mother (0/1) status.mother <- c(NA, NA, NA, NA, NA, NA, 1, 1, 1, 0, 0, 1, 1) # a measure of individual measure <- rnorm(13) test.data <- data.frame(id, year, year.hatch, year.1st.reprod, status, id.mother, status.mother, measure) test.data -------------------------------- I want to compare measures of individuals that have mothers of different status. But I need help to make the following subset of individuals: I want the measures that are taken on individuals the year they are hatched. So for the individuals I compare, I want year==year.hatch. ...and I also want that the individuals from which I obtain measurements are offspring from the first reproduction year of their parents. So for the individuals I compare, I want their /mothers/ to have year==year.1st.reproduction. Applying my selection criteria on the simple dummy data above, I would end up with the measures from id=3 in 1996, id=4 in 1996 and id=5 in 1997. Can anyone help me how to perform this subsetting in R? Thanks a lot in advance! Henrik -- ************************ Henrik Pärn Department of Biology Norwegian University of Science and Technology NO-7491 Trondheim Norge +47 735 96285 (office) +47 909 89 255 (mobile) +47 735 96100 (fax) ______________________________________________ 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.
