Adding a new column to a table

[ernijs12]

This is an example data with what I am working with:

tibble::tribble(
     ~item, ~quantity,
     "saw",        2L,
     "saw",        4L,
     "saw",        6L,
  "hammer",        1L,
  "hammer",        2L,
  "hammer",        3L
  )

I want to calculate mean for each item and create a new column that shows it

this is what I am trying to get:

tibble::tribble(
     ~item, ~quantity, ~mean,
     "saw",        2L,    4L,
     "saw",        4L,    4L,
     "saw",        6L,    4L,
  "hammer",        1L,    2L,
  "hammer",        2L,    2L,
  "hammer",        3L,    2L
  )

I tried this:

df <- df %>% 
  group_by(item) %>%
  mutate(
    mean = mean(quantity) 
  ) %>%
  ungroup()

but something is not working

[Ven]

Based on what you've provided I was able to reproduce what you were trying to get.

library(dplyr)

df <- tibble::tribble(
     ~item, ~quantity,
     "saw",        2L,
     "saw",        4L,
     "saw",        6L,
  "hammer",        1L,
  "hammer",        2L,
  "hammer",        3L
  )

# Using dplyr pipes
df <- df %>%
  group_by(item) %>%
  mutate(mean = mean(quantity)) %>%
  ungroup()

Output

# A tibble: 6 x 3
  item   quantity  mean
  <chr>     <int> <dbl>
1 saw           2     4
2 saw           4     4
3 saw           6     4
4 hammer        1     2
5 hammer        2     2
6 hammer        3     2

[ernijs12]

Could it be that other packaged are intervening and messing the result up?

[Ven]

Possible.

Did you receive an error when you ran this particular section?