I have records in a dataframe that I want to duplicate multiple times, and apply some changes to each iteration of duplicate rows.
Using the following dataframe:
name <- c("Kiwi","Orange","Apple")
val1 <- c(1,9,10)
val2 <- c(1,1,1)
df <- data.frame(name, val1, val2)
I can duplicate the row where name == "Apple" and replace the name in the duplicate row:
df.2 <- df %>%
filter(name == "Apple") %>%
mutate(name = "Strawberry") %>%
bind_rows(., df)
However running this operation more than once does not work as expected:
df.2 <- df %>%
filter(name == "Apple") %>%
mutate(name = "Strawberry") %>%
bind_rows(., df) %>%
filter(name == "Apple") %>%
mutate(name = "Dragonfruit") %>%
bind_rows(., df)
Expected result:
val1 <- c(10,10,1,9,10)
val2 <- c(1,1,1,1,1)
name <- c("Dragonfruit","Strawberry","Kiwi","Orange","Apple")
expected.result <- data.frame(name, val1, val2)
Here is another way of doing it:
df.2 <- bind_rows(df,
df %>% filter(name == "Apple") %>% mutate(name = "Strawberry"),
df %>% filter(name == "Apple") %>% mutate(name = "Dragonfruit"))
Of course, it's more concise to make a new variable for df %>% filter(name == "Apple"), and then use that, but not massively more, so I didn't, but you can.
To find the issue with your code, let's go through it line by line:
df.2 <- df %>%
filter(name == "Apple") %>%
mutate(name = "Strawberry") %>%
at this point, the dataframe is one row Strawberry 10 1
bind_rows(., df) %>%
this value is added to the beginning of the old dataframe
filter(name == "Apple") %>%
...but then you promptly remove it again, by filtering only for rows where the name is "Apple"
mutate(name = "Dragonfruit") %>%
bind_rows(., df)
hence, at the end, you don't have the strawberry row anymore.