Ifelse using And

Question

I have a sample dataset below:

Col1    Col2    Col3
   A       6       9  
   B       7      10
   C       8      11
   C       9      12
   D      10      13

How do I do an ifelse statement that says - "If Col1 does not have the values A and B, then make Col3 = Col2, if not, keep original values."

Final expected output:

Col1    Col2    Col3
   A       6       9  
   B       7      10
   C       8       8
   C       9       9
   D      10      10

This was my attempt but it didn't work:

df$Col3 <- ifelse(df$Col1!="A" & df$Col1!="B", df$Col2, df$Col3)

When I run your example it works. Is there something specific that goes wrong? — joran, Jan 09 '19 at 22:49
What's the structure of your df? Are the variables, factors? — Khaynes, Jan 09 '19 at 23:01

Eric · Accepted Answer · 2019-01-09T22:47:07.320

2

library(dplyr)    
df %>%
  mutate(Col3 = ifelse(Col1 %in% c("A","B"),Col3,Col2))

edited Jan 09 '19 at 22:47

answered Jan 09 '19 at 22:46

Eric

1

Why do you need to load all `tidyverse` for this? – pogibas Jan 09 '19 at 22:46
you don't. `dplyr` is enough, I guess. – Eric Jan 09 '19 at 22:49

score 0 · Answer 2 · answered Jan 09 '19 at 23:14

0

Here is the true answer to your question:

As for code which will work, case_when is a much more useful implementation

library(dplyr)

df %>%
  mutate(Col3 = case_when(
    Col1 %in% c("A","B") ~ Col3,
    TRUE ~ Col2
    )
  )

answered Jan 09 '19 at 23:14

glaucon

This is completely unrelated to your linked question. – Matthew Lundberg Jan 09 '19 at 23:16
Did you read this? “So ifelse is intended for the specific purpose of testing a vector of booleans and returning a vector of the same length, filled with elements taken from the (vector) yes and no arguments.” – glaucon Jan 09 '19 at 23:48
His vector is the same length as the intended result. Yes, I read both questions. Note that the comment above says nothing about the solution you have provided. Just that the linked question is about something else entirely. – Matthew Lundberg Jan 09 '19 at 23:54
Reviewing the initial input, I was unable to produce an error at all (lol). That fact alone renders both my link & the solution useless! It is certainly unrelated as a result. Cheers – glaucon Jan 10 '19 at 00:13

2 Answers2