Count Observations Meeting Certain Criteria by Group R-CodePudding

I need some help counting observations meeting certain criteria by group. I first want the number of employees by location as a column. Then I would like to retrieve the number of employees that have worked more than 40 hours (by location) and summarize that into a column. I assume there is an easy way to do it with dplyr or base R but I'm stumped. My data is below.

name       hours_worked  location
Bob        55            IL
Nick       25            IL 
Sally      30            IL
Patricia   50            WI
Tim        35            WI
Liz        42            OH
Brad       60            OH
Sam        48            OH

Ideal output would be something like:

location   headcount   over_40 
IL            3          1
WI            2          1
OH            3          3

CodePudding user response：

We can do a group by operation - grouped by 'location' get the number of rows (n()) for headcount and the sum of logical vector to get the count of 'over_40'

library(dplyr)
df1 %>% 
   group_by(location) %>% 
   summarise(headcount = n(), over_40 = sum(hours_worked > 40))

-output

# A tibble: 3 x 3
  location headcount over_40
  <chr>        <int>   <int>
1 IL               3       1
2 OH               3       3
3 WI               2       1

data

df1 <- structure(list(name = c("Bob", "Nick", "Sally", "Patricia", "Tim", 
"Liz", "Brad", "Sam"), hours_worked = c(55L, 25L, 30L, 50L, 35L, 
42L, 60L, 48L), location = c("IL", "IL", "IL", "WI", "WI", "OH", 
"OH", "OH")), class = "data.frame", row.names = c(NA, -8L))