  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.calandra@uni-hamburg.de

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