R Assign Values based on multiple conditions-CodePudding

I am new to R and I need new help filling an existing column based on conditions in two others.

The dataframe is called A.

If the columns box=6 AND document = 75 then size= big.

I have tried multiple options I found online but R keeps making them out to be an error. I would appreciate it if someone can give me the code line. Thank you

CodePudding user response：

Without more details (i.e. a reproducible example) it is difficult to know whether this answers your question or not, but here is a potential solution:

set.seed(3)
A <- data.frame(box = sample(5:7, size = 50, replace = TRUE),
                document = sample(74:76, size = 50, replace = TRUE))

A$size <- ifelse(A$box == 6 & A$document == 75, "big", "other")
head(A, 10)
#>    box document  size
#> 1    5       76 other
#> 2    6       76 other
#> 3    7       75 other
#> 4    6       75   big
#> 5    7       74 other
#> 6    7       76 other
#> 7    6       75   big
#> 8    7       74 other
#> 9    5       75 other
#> 10   6       74 other

Another potential solution is to use case_when() from the dplyr package:

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

A <- data.frame(box = sample(5:7, size = 50, replace = TRUE),
                document = sample(74:76, size = 50, replace = TRUE))
A %>%
  mutate(size = case_when(box == 6 & document == 75 ~ "big",
                          box < 6 & document < 75 ~ "small",
                          document < 75 ~ "medium",
                          TRUE ~ "other"))
#>    box document   size
#> 1    6       75    big
#> 2    6       74 medium
#> 3    7       76  other
#> 4    5       75  other
#> 5    6       76  other
#> 6    5       75  other
#> 7    6       76  other
#> 8    5       74  small
#> 9    5       74  small
#> 10   6       74 medium
#> ...

^{Created on 2021-11-08 by the reprex package (v2.0.1)}