Finding equal rows between dataframes in R-CodePudding

I have the following data set as example:

df1 <- data.frame(V1 = 1:10, V2 = 1:10, V3 = 1:10)
df2 <- data.frame(V1 = 5:1, V2 = 5:1, v3 = c(1, 4, 5, 2, 3))

If a row in df1 are present in df2, I would create a column in df1 that indicates the corresponding row to the df2 and for other rows showed FALSE or NULL or NA or 0 or ...

output expected:

   V1 V2 V3 rows_matched
1   1  1  1        FALSE
2   2  2  2            4
3   3  3  3        FALSE
4   4  4  4            2
5   5  5  5        FALSE
6   6  6  6        FALSE
7   7  7  7        FALSE
8   8  8  8        FALSE
9   9  9  9        FALSE
10 10 10 10        FALSE

Thank you

CodePudding user response：

You can do a simple left join. Note: I fixed the column name in df2 from v3 to V3 to match the names of df1

left_join(
  df1, 
  df2 %>% mutate(rows_matched=row_number())
)

Output:

   V1 V2 V3 rows_matched
1   1  1  1           NA
2   2  2  2            4
3   3  3  3           NA
4   4  4  4            2
5   5  5  5           NA
6   6  6  6           NA
7   7  7  7           NA
8   8  8  8           NA
9   9  9  9           NA
10 10 10 10           NA

CodePudding user response：

in Base R:

cbind(df1, matched = match(interaction(df1), interaction(df2)))

   V1 V2 V3 matched
1   1  1  1      NA
2   2  2  2       4
3   3  3  3      NA
4   4  4  4       2
5   5  5  5      NA
6   6  6  6      NA
7   7  7  7      NA
8   8  8  8      NA
9   9  9  9      NA
10 10 10 10      NA