Issues with replacing all words in a string except one

Question

I have a simple problem:

I have a column with thousands of values and I'm trying to convert it into a dichotomous variable (Yes|No). Replacing strings with 'No' was easy enough as the value I was converting was a single asterisk

Data$Complete <- gsub("\\*", "No", Data$Complete)

But when I attempt to replace everything apart from 'No', the following code replaces everything with 'Yes' in my string. I don't understand why it would as I'm specifying to replace everthing apart from "No":

Data$Complete <- Data[!Data$Complete %in% c("No"), "Complete"] <- "Yes"

Any pointers would be appreciated.

Try using `ifelse` and replace them with a single command: `ifelse(grepl("\\*", foo), "No", "Yes")` — pogibas, Jul 19 '18 at 10:40
Anyway you have two `<-`. Try `Data[!Data$Complete %in% c("No"), "Complete"] <- "Yes"` — s_baldur, Jul 19 '18 at 10:40
Related: https://stackoverflow.com/questions/48261387/how-to-conditionally-replace-values-in-r-data-frame-using-if-then-statement — pogibas, Jul 19 '18 at 10:41
If you have to compare to just one value, `"No"`, you don't need `%in%`, you should use `==`. — Rui Barradas, Jul 19 '18 at 10:43

score 0 · Accepted Answer · answered Sep 20 '18 at 18:50

You can use combination of ifelse function and grepl to extract necessary data as below:

library(stringi)

# data simulation
set.seed(123)
n <- 1000
data <- data.frame(
  complete = stri_rand_strings(n = n, length = 20, pattern = "[A-Za-z0-9\\*]")
)

# string matching
data$yes_no <- ifelse(grepl("\\*", data$complete), "No", "Yes")
head(data)

Output:

              complete yes_no
1 HmOsw1WtXRxRfZ5tE1Jx    Yes
2 tgdzehXaH8xtgn0TkCJD    Yes
3 7PPM87DSFr1Qn6YC7ktM    Yes
4 e4NGoRoonQkch*SCMbL6     No
5 EfPm5QztsA7eKeJAm4SV    Yes
6 aJTxTtubO8vH2wi7XxZO    Yes

Issues with replacing all words in a string except one

1 Answers1