Subsetting based on values of a different data frame in R

Question

I want to subset data if every value in the row is greater than the respective row in a different data frame. I also need to skip some top rows. These previous questions did

Answer 1

I think it is better to use SQL for such inter table filtering. It is clean and readable( You keep the rules logic).

 library(sqldf)
sqldf('SELECT DISTINCT A.*
        FROM A,B
        WHERE A.name1   > B.name1
        AND    A.name2  > B.name2')
  name1 name2
1   trt  ctrl
2    10    10

Answer 2

requisite data.table solution:

library(data.table)

# just to preserve the order, non-alphabetically
idsA <- factor(rownames(A), levels=rownames(A))
idsB <- factor(rownames(B), levels=rownames(B))

# convert to data.table with id
ADT <- data.table(id=idsA, A, key="id")
BDT <- data.table(id=idsB, B, key="id")

# filter as needed
ADT[BDT][name1 > name1.1 & name2 > name2.1, list(id, name1, name2)]

Answer 3

If I rename your matrices amat and bmat, then

amat[which(sapply(1:nrows(amat),function(x) prod(amat[x,]>bmat[x,]))==1),]
[1] 10 10

And you can paste the 'hours' row back on if desired.

Answer 4

N <- nrow(A)
cond <- sapply(3:N, function(i) sum(A[i,] > B[i,])==2)
rbind(A[1:2,], subset(A[3:N,], cond))