CODEWITHSUNDEEP
rconditional-statementsrowsubset
Sophie S
Sophie S

Reputation: 11

Remove the following row if a condition is met

I would like to remove all rows that are followed by the same entry in R. I have the following column in a data frame:

"FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE" "FAILURE" "HIT"     "FAILURE" "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE" "FAILURE" "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE" "HIT"    "FAILURE" "HIT"     "FAILURE" "FAILURE" "FAILURE" "HIT"

I would like to delete all rows in which the "FAILURE" entry is followed by another "FAILURE" entry. So I would like to get the following column of the data frame back:

"FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE"  "HIT" "FAILURE" "HIT"     "FAILURE" "HIT" "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE" "HIT"    "FAILURE" "HIT" "FAILURE" "HIT"

How can I check if the next row meets that condition and remove those rows?

Upvotes: 0

Views: 61

Answers (1)

GKi
GKi

Reputation: 39647

All which had a hit with FAILURE and their diff is 0 are removed with:

. <- x == "FAILURE"
(. <- x[!(. & diff(c(FALSE, .)) == 0)])
# [1] "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE"
# [8] "HIT"     "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE" "HIT"    
#[15] "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE"
#[22] "HIT"     "FAILURE" "HIT"     "FAILURE" "HIT"     "FAILURE" "HIT"    

identical(., y)
#[1] TRUE

Data:

x <- c("FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "FAILURE", "HIT", "FAILURE", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "FAILURE", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "FAILURE", "FAILURE", "HIT")

y <- c("FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT", "FAILURE", "HIT")

Upvotes: 1

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