CODEWITHSUNDEEP
r
Ariel Mitchell
Ariel Mitchell

Reputation: 11

Removing a value from R

Is there a way to remove specific values using R programming?

For example, I have a variable named Survive. This variable has input values such as "Y", "N", and "U". Is there a code to remove all the "U" values?

I am fairly new to R and tried this code:

project$Survive = "U"<-NULL

which obviously did not work.

Upvotes: 0

Views: 1053

Answers (1)

Marcelo Avila
Marcelo Avila

Reputation: 2374

Here are two possible soutions. One filtering (dropping) observations where Survive is "U" and the other just transforming to a missing value (NA) using the package dplyr. I would encourage looking at the package {dplyr}, which has a quite intuitive interface for data manipulation.

library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union

project <- tribble(
  ~id, ~Survive, ~value, 
  1,      "A",     42,
  1,      "U",     31,
  2,      "A",     21,
  2,      "U",     11
)

project %>% 
  # filter (keep) observations where survive is not equal to "U". 
  filter(Survive != "U")
#> # A tibble: 2 x 3
#>      id Survive value
#>   <dbl> <chr>   <dbl>
#> 1     1 A          42
#> 2     2 A          21


project %>% 
  # mutate "U" into character missing (NA) when Survive == "U". 
  mutate(Survive = if_else(Survive == "U", NA_character_, Survive))
#> # A tibble: 4 x 3
#>      id Survive value
#>   <dbl> <chr>   <dbl>
#> 1     1 A          42
#> 2     1 <NA>       31
#> 3     2 A          21
#> 4     2 <NA>       11


# base R approach for keeping a subset of observations.
(res_project <- subset(project, Survive != "U"))
#> # A tibble: 2 x 3
#>      id Survive value
#>   <dbl> <chr>   <dbl>
#> 1     1 A          42
#> 2     2 A          21

Created on 2021-07-04 by the reprex package (v2.0.0)

Upvotes: 1

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