Get daily average with R

Question

I have a data.frame with some prices per day. I would like to get the average daily price in another column (avg_price). How can I do that ?

                   date   price   avg_price
1   2017-01-01 01:00:00   10      18.75
2   2017-01-01 01:00:00   10      18.75
3   2017-01-01 05:00:00   25      18.75
4   2017-01-01 04:00:00   30      18.75
5   2017-01-02 08:00:00   10      20
6   2017-01-02 08:00:00   30      20
7   2017-01-02 07:00:00   20      20

maybe this page can help you? https://stackoverflow.com/questions/37575785/r-group-by-date-and-summarize-the-values — Omniswitcher, Sep 01 '22 at 09:14

score 1 · Accepted Answer · answered Sep 01 '22 at 09:13

library(lubridate)
library(tidyverse)

df %>%  
  group_by(day = day(date)) %>% 
  summarise(avg_price = mean(price))

# A tibble: 2 x 2
    day avg_price
  <int>     <dbl>
1     1      18.8
2     2      20  

df %>%  
  group_by(day = day(date)) %>%  
  mutate(avg_price = mean(price))

# A tibble: 7 x 4
# Groups:   day [2]
  date                price avg_price   day
  <dttm>              <dbl>     <dbl> <int>
1 2017-01-01 01:00:00    10      18.8     1
2 2017-01-01 01:00:00    10      18.8     1
3 2017-01-01 05:00:00    25      18.8     1
4 2017-01-01 04:00:00    30      18.8     1
5 2017-01-02 08:00:00    10      20       2
6 2017-01-02 08:00:00    30      20       2
7 2017-01-02 07:00:00    20      20       2

Get daily average with R

1 Answers1