Massaging data

massage_data.R

library(dplyr)
library(tidyr)

dat <- data.frame(laji=c("accgen", "accnis", "accgen", "accnis" , "accgen",
                         "accnis", "accgen", "accnis"),
                  lkm=c(2, 2, 1, 4, 3, 2, 2, 6),
                  linja_P_E = c("P", "P", "E", "E", "P", "P", "E", "E"))

dat_agg <- dat %>% 
  # Group by both laji and linja_P_E
  group_by(laji, linja_P_E) %>% 
  # Then calculate the total count per laji/linja_P_E
  summarise(
    lkm=sum(lkm)
  ) %>% 
  # Grouping set by group_by() is still on, let's ungroup the data
  ungroup() %>% 
  # Spread (pivot) the data in terms of linja_P_E -> creates cols "P" and "E".
  # spread is from tidyr
  spread(linja_P_E, lkm) %>%
  # Calculate the total count into a new column "lkm"
  mutate(lkm=P+E) %>% 
  # Reorder and rename the cols
  select(laji, lkm, lkm_P=P, lkm_E=E)