What does the error "condition has a length> 1 and only the first element will be used" mean?
Here is my dataset:
FullName <- c("Jimmy John Cephus", "Frank Chester", "Hank Chester", "Brody Buck Clyde", "Merle Rufus Roscoe Jed Quaid")
df <- data.frame(FullName)
Purpose: Look in FullName for any spaces, "" and extract FirstName.
My first step is to use the stringr library, because I will use the str_count () and word () functions.
Next, I test stringr::str_count(df$FullName, " ")
against df and return R:
[1] 2 1 1 2 4
This is what I expect.
Next, I test the word () function:
stringr::word(df$FullName, 1)
R returns:
[1] "Jimmy" "Frank" "Hank" "Brody" "Merle"
Again, this is what I expect.
Next, I create a simple UDF (user-defined function) that includes the str_count () function:
split_firstname = function(full_name){
x <- stringr::str_count(full_name, " ")
return(x)
}
split_firstname(df$FullName)
Again, R provides what I expect:
[1] 2 1 1 2 4
As a last step, I include the word () function in UDF and the code for all conditions:
split_firstname = function(full_name){
x <- stringr::str_count(full_name, " ")
if(x==1){
return(stringr::word(full_name,1))
}else if(x==2){
return(paste(stringr::word(full_name,1), stringr::word(full_name,2), sep = " "))
}else if(x==4){
return(paste(stringr::word(full_name,1), stringr::word(full_name,2), stringr::word(full_name,3), stringr::word(full_name,4), sep = " "))
}
}
Then I call UDF and pass it FullName from df:
split_firstname(df$FullName)
This time I did NOT get what I expected, R came back:
[1] "Jimmy John" "Frank Chester" "Hank Chester" "Brody Buck" "Merle Rufus"
Warning messages:
1: In if (x == 1) { :
the condition has length > 1 and only the first element will be used
2: In if (x == 2) { :
the condition has length > 1 and only the first element will be used
, R :
"Jimmy John", "Frank", "Hank", "Brody Buck", "Merle Rufus Roscoe Jed"
, if . , . case_when
dplyr
.
library(dplyr)
split_firstname <- function(full_name){
x <- stringr::str_count(full_name, " ")
case_when(
x == 1 ~ stringr::word(full_name, 1),
x == 2 ~ paste(stringr::word(full_name,1), stringr::word(full_name,2), sep = " "),
x == 4 ~ paste(stringr::word(full_name,1), stringr::word(full_name,2), stringr::word(full_name,3), stringr::word(full_name,4), sep = " ")
)
}
lukeA - , , , sapply from base-r rollise from dplyr
df$first <- sapply(df$FullName, split_firstname)
head(df)
FullName first
1 Jimmy John Cephus Jimmy John
2 Frank Chester Frank
3 Hank Chester Hank
4 Brody Buck Clyde Brody Buck
5 Merle Rufus Roscoe Jed Quaid Merle Rufus Roscoe Jed
library(dplyr)
df <- df %>% rowwise() %>%
mutate(split2 = split_firstname(FullName))
head(df)
FullName first split2
<fctr> <chr> <chr>
1 Jimmy John Cephus Jimmy John Jimmy John
2 Frank Chester Frank Frank
3 Hank Chester Hank Hank
4 Brody Buck Clyde Brody Buck Brody Buck
5 Merle Rufus Roscoe Jed Quaid Merle Rufus Roscoe Jed Merle Rufus Roscoe Jed