I have the following dataframe:
df = structure(list(Day = c(19L, 20L, 20L, 20L, 20L, 21L, 21L, 21L,
21L, 21L), Month = c(9, 9, 9, 9, 9, 9, 9, 9, 9, 9), Year = c(2004,
2004, 2004, 2004, 2004, 2004, 2004, 2004, 2004, 2004), Date = c("2004-09-19",
"2004-09-20", "2004-09-20", "2004-09-20", "2004-09-20", "2004-09-21",
"2004-09-21", "2004-09-21", "2004-09-21", "2004-09-21"), Outlet = c("Le Monde",
"Financial Times", "Corriere della Sera", "Frankfurter Allgemeine Zeitung",
"El Pais", "Financial Times", "La Tribune", "Financial Times",
"Borsen-Zeitung", "Borsen-Zeitung"), Country = c("France", "International",
"Italy", "Germany", "Spain", "Germany", "France", "Germany",
"Germany", "Germany")), row.names = c("text1", "text2", "text3",
"text4", "text5", "text6", "text7", "text8", "text9", "text10"
), class = "data.frame")
Day Month Year Date Outlet Country
text1 19 9 2004 2004-09-19 Le Monde France
text2 20 9 2004 2004-09-20 Financial Times International
text3 20 9 2004 2004-09-20 Corriere della Sera Italy
text4 20 9 2004 2004-09-20 Frankfurter Allgemeine Zeitung Germany
text5 20 9 2004 2004-09-20 El Pais Spain
text6 21 9 2004 2004-09-21 Financial Times Germany
text7 21 9 2004 2004-09-21 La Tribune France
text8 21 9 2004 2004-09-21 Financial Times Germany
text9 21 9 2004 2004-09-21 Borsen-Zeitung Germany
text10 21 9 2004 2004-09-21 Borsen-Zeitung Germany
I want to have an idex for every row that has the same Date as below:
Day Month Year Date Outlet Country ID
text1 19 9 2004 2004-09-19 Le Monde France 1
text2 20 9 2004 2004-09-20 Financial Times International 2
text3 20 9 2004 2004-09-20 Corriere della Sera Italy 2
text4 20 9 2004 2004-09-20 Frankfurter Allgemeine Zeitung Germany 2
text5 20 9 2004 2004-09-20 El Pais Spain 2
text6 21 9 2004 2004-09-21 Financial Times Germany 3
text7 21 9 2004 2004-09-21 La Tribune France 3
text8 21 9 2004 2004-09-21 Financial Times Germany 3
text9 21 9 2004 2004-09-21 Borsen-Zeitung Germany 3
text10 21 9 2004 2004-09-21 Borsen-Zeitung Germany 3
To do it, I do:
library(dplyr)
df %>% group_by(Date) %>% mutate(id = row_number())
Day Month Year Date Outlet Country id
1 19 9 2004 2004-09-19 Le Monde France 1
2 20 9 2004 2004-09-20 Financial Times International 1
3 20 9 2004 2004-09-20 Corriere della Sera Italy 2
4 20 9 2004 2004-09-20 Frankfurter Allgemeine Zeitung Germany 3
...
Yet, it doesn't work. I don't manage to understand why.
Can anyone help me solve this?
Thanks a lot!
We can use cur_group_id after grouping by 'Date'
library(dplyr)
df %>%
group_by(Date) %>%
mutate(ID = cur_group_id()) %>%
ungroup
Or another option is match without grouping
df %>%
mutate(ID = match(Date, unique(Date)))
Or using base R
df$ID <- with(df, match(Date, unique(Date)))