CODEWITHSUNDEEP
rdataframetibble
TheCodeNovice
TheCodeNovice

Reputation: 690

Adding two rows of a data frame together R

I am trying to address a few troublesome rows in a dataframe in R. My recourse is to simply add them together, consoldiating two rows into 1. So for example if I had a 100 rows with X columns, I would have 99 rows with X columns after the operation. Ideally I would just pass two row numbers and they would be combined. I would want to add each value for every column like a matrix operation almost. How can I do this?

Upvotes: 1

Views: 3471

Answers (1)

G. Grothendieck
G. Grothendieck

Reputation: 269644

Add the two rows together overwriting the second row and then remove the first row.

combine_rows <- function(data, row1, row2) {
  data[row2, ] <- data[row1, ] + data[row2, ]
  data[-row1, ]
}

# test using builtin data frame, BOD

BOD
##   Time demand
## 1    1    8.3
## 2    2   10.3
## 3    3   19.0
## 4    4   16.0
## 5    5   15.6
## 6    7   19.8

combine_rows(BOD, 2, 3)
##   Time demand
## 1    1    8.3
## 3    5   29.3   <-- this row is the sum of original rows 2 and 3
## 4    4   16.0
## 5    5   15.6
## 6    7   19.8

Upvotes: 3

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