CODEWITHSUNDEEP
rgroup-bycountcategorical-data
cc Li
cc Li

Reputation: 37

how to count and group categorical data by range in r

I have data from a questionnaire that has a column for year of birth. So the range of data was too large and my mapping became confusing. I'm now trying to take the years, group them up by decade decade, and then chart them. But I don't know how to group them.

my data is like：

birth_year <- data.frame("years"=c(
  "1920","1923","1930","1940","1932","1935","1942","1944","1952","1956","1996","1961",
  "1962","1966","1978","1987","1998","1999","1967","1934","1945","1988","1976","1978",
  "1951","1986","1942","1999","1935","1920","1933","1987","1998","1999","1931","1977",
  "1920","1931","1977","1999","1967","1992","1998","1984"
))

and my plot is like: enter image description here

However, I want my data by group as:

birth_year   count
(1920-1930]:  5
(1931-1940]:  8
(1941-1950]:  4
(1951-1960]:  3
(1961-1970]:  5
(1971-1980]:  5
(1981-1990]:  5
(1991-2000]:  9

and then plot as a range group.

Upvotes: 0

Views: 37

Answers (2)

Len Greski
Len Greski

Reputation: 10855

We can use cut() to group the data, and then plot with ggplot().

birth_year <- data.frame("years"=c(
     "1920","1923","1930","1940","1932","1935","1942","1944","1952","1956","1996","1961",
     "1962","1966","1978","1987","1998","1999","1967","1934","1945","1988","1976","1978",
     "1951","1986","1942","1999","1935","1920","1933","1987","1998","1999","1931","1977",
     "1920","1931","1977","1999","1967","1992","1998","1984"
))

birth_year$yearGroup <- cut(as.integer(birth_year$years),breaks = 8,dig.lab = 4,
                            include.lowest = FALSE)
library(ggplot2)

ggplot(birth_year,aes(x = yearGroup)) + geom_bar()

enter image description here

Upvotes: 1

Onyambu
Onyambu

Reputation: 79208

birth_year %>%
   mutate(val=cut_width(as.numeric(years),10,boundary = 1920, dig.lab=-1))%>%
   count(val)
          val n
1 [1920,1930] 5
2 (1930,1940] 8
3 (1940,1950] 4
4 (1950,1960] 3
5 (1960,1970] 5
6 (1970,1980] 5
7 (1980,1990] 5
8 (1990,2000] 9

Upvotes: 1

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