R: RunningTotal in the last 365 days window by Name

Question

This is what my data looks like. The rightmost column is my Desired Column.

Name  EventType  EventDate  SalesAmount RunningTotal Runningtotal(prior365Days)
J         


        

Answer 1

df$EventDate <- as.Date(df$EventDate, format="%d/%m/%Y")
df <- df %>%
   group_by (Name) %>%
   arrange(EventDate) %>% 
   mutate(day = EventDate - EventDate[1])

f <- Vectorize(function(i)
    sum(df[df$Name[i] == df$Name & df$day[i] - df$day >= 0 & 
             df$day[i] - df$day <= 365, "SalesAmount"]), vec="i")
df$RunningTotal365 <- f(1:nrow(df))