Multiply a grouped data frame by a matrix dplyr - r

Question

My problem:
I have two data frames, one for industries and one for occupations. They are nested by state, and show employment.
I also have a concordance matrix, which shows the weights of each of the occupations in each industry.
I would like to create a new employment number in the Occupation data frame, using the Industry employments and the concordance matrix.
I have made dummy version of my problem - which I think is clear:
Update
I have solved the issue, but I would like to know if there is a more elegant solution? In reality my dimensions are 7 States * 200 industries * 350 Occupations it becomes rather data hungry
# create industry data frame
set.seed(12345)
ind_df <- data.frame(State = c(rep("a", len =6),rep("b", len =6),rep("c", len =6)),
industry = rep(c("Ind1","Ind2","Ind3","Ind4","Ind5","Ind6"), len = 18),
emp = rnorm(18,20,2))
# create occupation data frame
Occ_df <- data.frame(State = c(rep("a", len = 5), rep("b", len = 5), rep("c", len =5)),
occupation = rep(c("Occ1","Occ2","Occ3","Occ4","Occ5"), len = 15),
emp = rnorm(15,10,1))
# create concordance matrix
Ind_Occ_Conc <- matrix(rnorm(6*5,1,0.5),6,5) %>% as.data.frame()
# name cols in the concordance matrix
colnames(Ind_Occ_Conc) <- unique(Occ_df$occupation)
rownames(Ind_Occ_Conc) <- unique(ind_df$industry)
# solution
Ind_combined <- cbind(Ind_Occ_Conc, ind_df)
Ind_combined <- Ind_combined %>%
group_by(State) %>%
mutate(Occ1 = emp*Occ1,
Occ2 = emp*Occ2,
Occ3 = emp*Occ3,
Occ4 = emp*Occ4,
Occ5 = emp*Occ5
)
Ind_combined <- Ind_combined %>%
gather(key = "occupation",
value = "emp2",
-State,
-industry,
-emp
)
Ind_combined <- Ind_combined %>%
group_by(State, occupation) %>%
summarise(emp2 = sum(emp2))
Occ_df <- left_join(Occ_df,Ind_combined)
My solution seems pretty inefficient, is there a better / faster way to do this?
Also - I am not quite sure how to get to this - but the expected outcome would be another column added to the Occ_df called emp2, this would be derived from Ind_df emp column and the Ind_Occ_Conc. I have tried to step this out for Occupation 1, essentially the Ind_Occ_Conc contains weights and the result is a weighted average.

Answer 1

I'm not sure about what you want to do with the sum(Ind$emp*Occ1_coeff) line but maybe that's what your looking for :
# Instead of doing the computation only for state a, get expected outcomes for all states (with dplyr):
Ind <- ind_df %>% group_by(State) %>%
summarize(rez = sum(emp))
# Then do some computations on Ind, which is a N element vector (one for each state)
# ...
# And finally, join Ind and Occ_df using merge
Occ_df <- merge(x = Occ_df, y = Ind, by = "State", all = TRUE)
Final output would then have Ind values in a new column: one value for all a, one value for b and one value for c.
Hope it will help ;)