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I have 5 common data frames that differ by year:

2010  
POLY STRA  Spp  breeders2010 nonbreeders2010   
1      1   mall     20             5  
1      1   cite     6              0  
1      3   mall     10             0   
2      1   gadw     6              2   

2011  
POLY STRA  Spp  breeders2011 nonbreeders2011   
1      1   mall     24             2  
1      1   cite     8              2  
1      3   mall     14             4   
2      1   gadw     8              4  

2012  
POLY STRA  Spp  breeders2012 nonbreeders2012   
1      1   mall     20             5  
1      1   cite     6              0  
1      3   mall     10             0   
2      1   gadw     6              2

I need to merge these 5 data frames by POLY, STRA and Spp such that the final result looks like: 

POLY STRA  Spp  breeders2010 nonbreeders2010 breeders2011 nonbreeders2011 breeders2012 nonbreeders2012 breeders2013 nonbreeders2013 breeders2014 nonbreeders2014     
1      1   mall     20            5               24            2             20             5 .....  
1      1   cite     6             0               8             2             6              0 ......  
1      3   mall     10            0               14            4             10             0 .....  
2      1   gadw     6             2               8             4             6              2 .....

I have tried merge and cbind and I cannot get columns to line up properly.

Brian Tompsett - 汤莱恩
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woodduck
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1 Answers1

4

I think merge should be just fine. For several data frames you can use Reduce:

Reduce(merge, list(df1, df2, df3, df4, df5))

If there are any missing rows in any of the data frames all = TRUE may help:

Reduce(function(x, y) merge(x, y, all = TRUE), list(df1, df2, df3, df4, df5))
bergant
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  • Can you help me with this question [http://stackoverflow.com/questions/35484595/data-frame-merge-and-selection-of-values-which-are-common-in-2-data-frames] – user3253470 Feb 18 '16 at 16:25