my df
> df <- data.frame(food = c("fruit banana", "fruit apple", "fruit grape", "bread", "meat"), sold = rnorm(5, 100))
> df
food sold
1 fruit banana 99.47171
2 fruit apple 99.40878
3 fruit grape 99.28727
4 bread 99.15934
5 meat 100.53438
Now I want to replace all values in food that starts with "fruit" and then group by food and summarise sold with sum sold.
> df %>%
+ mutate(food = replace(food, str_detect(food, "fruit"), "fruit")) %>%
+ group_by(food) %>%
+ summarise(sold = sum(sold))
Source: local data frame [3 x 2]
food sold
(fctr) (dbl)
1 bread 99.15934
2 meat 100.53438
3 NA 298.16776
Why is this command not working? It gives me NA instead of fruit?
It is working for me, I think your data is in factors:
Using stringsAsFactors=FALSE
while making the data as below or you can run options(stringsAsFactors=FALSE)
in the R environment to avoid the same:
df <- data.frame(food = c("fruit banana", "fruit apple", "fruit grape", "bread", "meat"), sold = rnorm(5, 100),stringsAsFactors = FALSE)
df %>%
mutate(food = replace(food, str_detect(food, "fruit"), "fruit")) %>%
group_by(food) %>%
summarise(sold = sum(sold))
Output:
# A tibble: 3 × 2
food sold
<chr> <dbl>
1 bread 99.67661
2 fruit 300.28520
3 meat 99.88566