Hi, Take a look at ?duplicated and ?unique
HTH, Ivan Le 9/22/2010 16:55, AndrewPage a écrit : > Hi all, > > I'm looking at a large data set, and I'm interested in removing rows where > only one variable is duplicated. Here's an example: > >> presidents > Qtr1 Qtr2 Qtr3 Qtr4 > 1945 NA 87 82 75 > 1946 63 50 43 32 > 1947 35 60 54 55 > 1948 36 39 NA NA > 1949 69 57 57 51 > 1950 45 37 46 39 > 1951 36 24 32 23 > 1952 25 32 NA 32 > 1953 59 74 75 60 > 1954 71 61 71 57 > 1955 71 68 79 73 > 1956 76 71 67 75 > 1957 79 62 63 57 > 1958 60 49 48 52 > 1959 57 62 61 66 > 1960 71 62 61 57 > 1961 72 83 71 78 > 1962 79 71 62 74 > 1963 76 64 62 57 > 1964 80 73 69 69 > 1965 71 64 69 62 > 1966 63 46 56 44 > 1967 44 52 38 46 > 1968 36 49 35 44 > 1969 59 65 65 56 > 1970 66 53 61 52 > 1971 51 48 54 49 > 1972 49 61 NA NA > 1973 68 44 40 27 > 1974 28 25 24 24 > > See how in 1954 and 1955, the Qtr1 approval rating is the same? Let's say I > wanted to return the presidents data frame, but only have unique values for > Qtr1. I doesn't matter which years are displayed for duplicated values-- it > just matters that each value is not displayed more than once. Any way I can > do this but still have it be a data frame that shows Qtr2, 3, and 4 values? > > Thanks in advance, > Andrew -- Ivan CALANDRA PhD Student University of Hamburg Biozentrum Grindel und Zoologisches Museum Abt. Säugetiere Martin-Luther-King-Platz 3 D-20146 Hamburg, GERMANY +49(0)40 42838 6231 ivan.calan...@uni-hamburg.de ********** http://www.for771.uni-bonn.de http://webapp5.rrz.uni-hamburg.de/mammals/eng/mitarbeiter.php [[alternative HTML version deleted]]
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