How to use grep or any other method to compare different no of row in two data frame and get the match and mismatch?

Question

Below are my two dataframe:

ABData1 <- data.frame(id=c(11,12,13,14,15),
                      a = c(1,2,3,4,5))
ABData2 <- data.frame(id=c(11,12,13,14),
                      b = c(1,4,3,4))

how to compare these two dataframe for matching rows and mismatch rows

if 1st row of ABData1 of a is matching with 1st row of ABData2 of b is matching then show as match and else show as mismatch and then goes to 2nd row....all the comparison will rowwise.

i have tried below code which is working fine for one data frame but its trowing error because of different rows in two data frames.

ABData <- data.frame(a = c(1,2,2,1,1),
                     b = c(1,2,1,1,2))

    match<- ABData %>% rowwise() %>% filter(grepl(a,b, fixed = TRUE))
    
    mismatch<- ABData %>% rowwise() %>% filter(!grepl(a,b))

I am expecting below output

Expected match Output:

id    a     expected    b
11    1     1           1
13    3     3           3
14    4     4           4
Expected mismatch output:

id    a     expected    b
12    2     2           4
15    NA    NA          5

Thanks in advance.

Answer 1

You can use this:

ABData1 <- data.frame(a = c(1,2,3,4,5))
ABData2 <- data.frame(b = c(1,4,3,4))

equLength <- function(x, y) {
  if (length(x)>length(y)) length(y) <- length(x) else length(x) <- length(y)
  data.frame(a=x, b=y)
}

ABData <- equLength(ABData1$a, ABData2$b)

... and then use your working code for one dataframe.

library("dplyr")
resultMatch <- ABData %>% rowwise() %>% filter(grepl(a,b, fixed = TRUE))
resultMismatch <- ABData %>% rowwise() %>% filter(!grepl(a,b))

---

For the extended question:

library("dplyr")

ABData1 <- data.frame(id=c(11,12,13,14,15),  a = c(1,2,3,4,5))
ABData2 <- data.frame(id=c(11,12,13,14),  b = c(1,4,3,4))

equLength <- function(x, y) {
  if (length(x)>length(y)) length(y) <- length(x) else length(x) <- length(y)
  data.frame(a=x, b=y)
}

if (nrow(ABData1)>nrow(ABData2)) ABData <- data.frame(ABData1, b=equLength(ABData1$a, ABData2$b)$b) else
  ABData <- data.frame(ABData2, a=equLength(ABData1$a, ABData2$b)$a)
  
resultMatch <- ABData %>% rowwise() %>% filter(grepl(a,b, fixed = TRUE))
resultMismatch <- ABData %>% rowwise() %>% filter(!grepl(a,b))