How to merge rows based on conditions with characters values? (Household data) - r

Question

I have a data frame in which the first column indicates the work (manager, employee or worker), the second indicates whether the person works at night or not and the last is a household code (if two individuals share the same code then it means that they share the same house).
#Here is the reproductible data :
PCS <- c("worker", "manager","employee","employee","worker","worker","manager","employee","manager","employee")
work_night <- c("Yes","Yes","No", "No","No","Yes","No","Yes","No","Yes")
HHnum <- c(1,1,2,2,3,3,4,4,5,5)
df <- data.frame(PCS,work_night,HHnum)
My problem is that I would like to have a new data frame with households instead of individuals. I would like to group individuals based on HHnum and then merge their answers.
For the variable "PCS" I have new categories based on the combination of answers : Manager+work ="I" ; manager+employee="II", employee+employee=VI, worker+worker=III etc
For the variable "work_night", I would like to apply a score (is both answered Yes then score=2, if one answered YES then score =1 and if both answered No then score = 0).
To be clear, I would like my data frame to look like this :
HHnum PCS work_night
1 "I" 2
2 "VI" 0
3 "III" 1
4 "II" 1
5 "II" 1
How can I do this on R using dplyr ? I know that I need group_by() but then I don't know what to use.
Best,
Victor

Answer 1

Here is one way to do it (though I admit it is pretty verbose). I created a reference dataframe (i.e., combos) in case you had more categories than 3, which is then joined with the main dataframe (i.e., df_new) to bring in the PCS roman numerals.
library(dplyr)
library(tidyr)
# Create a dataframe with all of the combinations of PCS.
combos <- expand.grid(unique(df$PCS), unique(df$PCS))
combos <- unique(t(apply(combos, 1, sort))) %>%
as.data.frame() %>%
dplyr::mutate(PCS = as.roman(row_number()))
# Create another dataframe with the columns reversed (will make it easier to join to the main dataframe).
combos2 <- data.frame(V1 = c(combos$V2), V2 = c(combos$V1), PCS = c(combos$PCS)) %>%
dplyr::mutate(PCS = as.roman(PCS))
combos <- rbind(combos, combos2)
# Get the count of "Yes" for each HHnum group.
# Then, put the PCS into 2 columns to join together with "combos" df.
df_new <- df %>%
dplyr::group_by(HHnum) %>%
dplyr::mutate(work_night = sum(work_night == "Yes")) %>%
dplyr::group_by(grp = rep(1:2, length.out = n())) %>%
dplyr::ungroup() %>%
tidyr::pivot_wider(names_from = grp, values_from = PCS) %>%
dplyr::rename("V1" = 3, "V2" = 4) %>%
dplyr::left_join(combos, by = c("V1", "V2")) %>%
unique() %>%
dplyr::select(HHnum, PCS, work_night)