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I would like to subset my dataframe by removing rows which have same values in a specific column.

Here my dataframe:

        ID    Area        Date    Day 
1    21009  4390.0  1979-12-27   4835 
2    24005   178.5  1979-12-27   4835
3    27001   484.3  1979-12-27   4835   
4    27002   758.9  1979-12-27   4835  
5    38003   133.9  1979-12-27   4835
6    33014   272.0  2004-02-01  13637    
7    33029    98.8  2004-02-01  13637     
8    34003   164.7  2004-02-01  13637   
9    23118   220.8  2007-01-18  14502

My output should be:

     ID    Area        Date    Day 
1    21009  4390.0  1979-12-27   4835 
2    33014   272.0  2004-02-01  13637       
3    23118   220.8  2007-01-18  14502

I tried but didn't work:

df <- subset(df, Day == unique(Day))

and

df <- df[df == unique(df$Day), ]

Whereas the following code only return me a vector with unique(df$Day), which is good, but I need all the dataframe subsetted: 

df <- unique(df[ , 4] )
user2100721
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1 Answers1

1

Use duplicated: 

df[!duplicated(df$Day), ]

#      ID   Area       Date   Day
# 1 21009 4390.0 1979-12-27  4835
# 6 33014  272.0 2004-02-01 13637
# 9 23118  220.8 2007-01-18 14502
Alex
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