Nesting ifelse in R

user_13519699 0
Viewed 64

I'm trying to nest ifelse in R to create a new vector C, where if both vectors A and B are missing, then NA; otherwise, if either vector contains 1, then "Yes"; otherwise, "No". Example:

A  B  C
1  1  Yes
1  0  Yes
0  1  Yes
0  0  No
NA 1  Yes
0  NA No
NA NA NA

The below is what I've been playing around with in various iterations, but I can't get it to work correctly. Any suggestions? 

df <- df %>% mutate(C=ifelse((is.na(A) & is.na(B)), NULL, ifelse((A==1 | B==1), "Yes", "No")))

(Perhaps there's a better way which doesn't use ifelse at all, which I'd also be open to, but for my own understanding it would be nice to know how to get this way to work as well!)

Many thanks!

if-statement r
4 Answers

Here is an alternative to ifelse():

df$C <- c("No", "Yes")[(rowMeans(df, na.rm = TRUE) > 0) + 1]

df
   A  B    C
1  1  1  Yes
2  1  0  Yes
3  0  1  Yes
4  0  0   No
5 NA  1  Yes
6  0 NA   No
7 NA NA <NA>
user_28352610

One option via nested ifelse:

df$C <- ifelse(rowSums(df, na.rm = TRUE) > 0,
    "Yes",
    ifelse(rowSums(is.na(df)) < 2,
        "No",
        "NA"
    )
)

which gives

> df
   A  B   C
1  1  1 Yes
2  1  0 Yes
3  0  1 Yes
4  0  0  No
5 NA  1 Yes
6  0 NA  No
7 NA NA  NA

Data

df <- structure(list(A = c(1L, 1L, 0L, 0L, NA, 0L, NA), B = c(1L, 0L, 
1L, 0L, 1L, NA, NA)), row.names = c(NA, -7L), class = "data.frame")
user_121587570

One option would be to use case_when function from dplyr package. 

# This was not tested, but should give your a flavour of how it might work
df <- df %>% mutate(
  C = dplyr::case_when(
    is.na(A) & is.na(B) ~ NA,
    A == 1 | B == 1 ~ "Yes",
    TRUE ~ "No"
  )
)
user_5999110

In base R, you could do somehting like : 

df$C <- ifelse(is.na(df$A)*is.na(df$B),NA,ifelse(ifelse(is.na(df$A),FALSE,df$A==1) + ifelse(is.na(df$B),FALSE,df$B==1)>0,"Yes","No"))

?

user_84252700
Related