Using dplyr and stringr to replace all values starts with

dplyr, r, stringr

Solution

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

Problem

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?

Original source