Calculating area proportion by multiple categories in r-CodePudding

This is my sample data

  grid_id_2 building_area_in  area new_bu_class
1     50871              352 10001       Public
2     51448               54 10001       Others
3     51448                0 10001       Others
4     51451              555 10001       Others
5     51450             1610 10001       Others
6     51451              555 10001       Others

> dput(data_subset)
structure(list(grid_id_2 = c(50871L, 51448L, 51448L, 51451L, 
51450L, 51451L, 51450L, 50682L, 50681L, 50682L), building_area_in = c(352L, 
54L, 0L, 555L, 1610L, 555L, 1610L, 12L, 219L, 818L), area = c(10001L, 
10001L, 10001L, 10001L, 10001L, 10001L, 10001L, 10001L, 10001L, 
10001L), new_bu_class = c("Public", "Others", "Others", "Others", 
"Others", "Others", "Others", "Public", "Public", "Public")), row.names = c(NA, 
10L), class = "data.frame")

I am trying to compute the building class area per grid id. Therefore, I want to calculate "building_area_in" proportion by each "new_bu_class" per "grid_id_2"

My expected output will look like this:

  grid_id_2 building_area_in  area new_bu_class class_propotion_Others class_propotion_Public total_area
1     50871              352 10001       Public                      0                   0.35        352
2     51448               54 10001       Others                  0.005                      0         54
3     51451              555 10001       Others                   0.11                      0       1110
4     51450             1610 10001       Others                   0.16                      0       1610

Thank you in advance!

CodePudding user response：

library(dplyr)

df %>% 
  group_by(grid_id_2) %>% 
  mutate(
    class_prop_others = if_else(new_bu_class == "Others",building_area_in/area,0),
    class_prop_public = if_else(new_bu_class == "Public",building_area_in/area,0),
    total_area = sum(building_area_in,na.rm = TRUE)
  )