r - Addining row number of sub dataframe -

i have following dataframe:

> df1   var1 var2 var3 1   ac   bc   bc 2   bc   bc   cc 3   dc   ec   dc 4   gc   gc   gc 

i have sub dataframe above df1 (only 2 rows remained of 4):

> df2   var1 var2 var3 2   bc   bc   cc 3   dc   ec   dc 

i numbers of df2 r (r = 2,3). in addition add df1 new column indicate 1 row exists in df2. in final df1 following:

> df1   var1 var2 var3 df2 1   ac   bc   bc  0 2   bc   bc   cc  1 3   dc   ec   dc  1 4   gc   gc   gc  0 

how can it?

we can use %in%to compare rownames of 'df1' , 'df2'. logical vector can coerced binary format wrapping +.

 df1$newcol <- +(rownames(df1) %in% rownames(df2))  df1  #  var1 var2 var3 newcol  #1   ac   bc   bc      0  #2   bc   bc   cc      1  #3   dc   ec   dc      1  #4   gc   gc   gc      0 

if need row names common, use intersect

intersect(rownames(df1), rownames(df2)) #[1] "2" "3"