I have two dataframes. I would like to match the rownames of the two dataframes, and if the rownames won’t match, I would like to remove theses rows from both dataframe to match the dimension of rows.
Dataframe A:
5002T 0 1
B01167 1 0
C1329 1 0
dim(3, 3)
Dataframe B:
5002T 4
B41167 3
C1329 8
2C134 1
dim(4, 2)
The Output will be look like the following:
Dataframe A_New:
5002T 0 1
C1329 1 0
dim(2, 3)
Dataframe B_New:
5002T 4
C1329 8
dim(2, 2)
Here is the code which I have tried to match the rownames:
match <- rownames(A) %in% rownames(B)
sum(!match)
How can I remove the unmatched rows from both dataframes and get the same dimension.
>Solution :
You were close.
dfa[rownames(dfa) %in% rownames(dfb), ]
# V2 V3
# X5002T 0 1
# C1329 1 0
dfb[rownames(dfb) %in% rownames(dfa), , drop=FALSE]
# V2
# X5002T 4
# C1329 8
However, it might be easier using intersect.
mtch <- intersect(rownames(dfa), rownames(dfb))
dfa[mtch, ]
# V2 V3
# X5002T 0 1
# C1329 1 0
dfb[mtch, , drop=FALSE]
# V2
# X5002T 4
# C1329 8
Note: drop=FALSE is needed because in this special case R would coerce a one-columned data frame in a vector.
Data:
dfa <- structure(list(V2 = c(0L, 1L, 1L), V3 = c(1L, 0L, 0L)), row.names = c("X5002T",
"B01167", "C1329"), class = "data.frame")
dfb <- structure(list(V2 = c(4L, 3L, 8L, 1L)), row.names = c("X5002T",
"B41167", "C1329", "X2C134"), class = "data.frame")