CODEWITHSUNDEEP
rdataframeduplicatesrow
B-Z
B-Z

Reputation: 83

R - How can we delete rows based on logical argument between two columns value

I wanted to know how I could delete the rows where the values in two different columns is not the same. Here is an example to illustrate my problem:

test.1 <- c("A", "B", "C", "D")
test.2 <- c("2009-02", "2009-04", "2010-01", "2011-02")
test.3 <- c("2009-02", "2009-08", "2010-01", "2013-06")
test.data <- data.frame(test.1, test.2, test.3)

which gives:

test.1  test.2  test.3
1      A 2009-02 2009-02
2      B 2009-04 2009-08
3      C 2010-01 2010-01
4      D 2011-02 2013-06

I would like to delete the rows where test.2 & test.3 are not equal, i.e. the second and fourth rows. I tried with the function duplicated as I found that 

test.data.2 = test.data[!duplicated(test.data[,c('test.2', 'test.3')]),]

would remove the rows where test.2 = test.3. Therefore, I remove "!" as followed:

test.data.2 = test.data[duplicated(test.data[,c('test.2', 'test.3')]),]

but it is not working. Would you have any other suggestions? Thank you very much for your help

Upvotes: 1

Views: 495

Answers (3)

Gaurav Bansal
Gaurav Bansal

Reputation: 5660

You can create a new dataframe where only the values where test.2 and test.3 are the same:

test.data.2 <- test.data[test.data$test.2 == test.data$test.3,]

Likewise, you can filter out values where they are not the same:

test.data.2 <- test.data[-which(test.data$test.2 != test.data$test.3),]

Upvotes: 1

Ben
Ben

Reputation: 30474

With tidyverse:

library(tidyverse)

test.data %>%
  filter(test.2 == test.3)

Or base R:

test.data[test.data$test.2 == test.data$test.3,]

Upvotes: 1

akrun
akrun

Reputation: 887118

We can use subset to subset the rows from base R

subset(test.data, test.2 == test.3)

Or using dplyr

library(dplyr)
test.data %>%
      slice(which(test.2 == test.3))

Upvotes: 1

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