Update decile.R

decile.R

@@ -7,21 +7,35 @@ library(data.table)
 
 decile_dt <-  function(x, decreasing = TRUE) {
   
-  # browser()
+  # x should be a numeric vector
+  # Data with 0 or with NA are marked to restore them when required
+  # Use decreasing = TRUE for cases where D10 > D9 > D8...
+  # Use decreasing = FALSE for cases where D1 > D2 > D3...
+  # D0 is always for cases where the vector is 0 or NA
   
   NA_positions = (is.na(x) | (x == 0))
   
+  # Convert to data.table
   x = as.data.table(x = x)
   
+  # set NA values as 0
   x[is.na(x), x := 0][
+    # add vector to maintain original order
     , num := .I][
+      # sort by decreasing order of X
       order(-x)][
+        # calculate cumulative sums by this order
         , cumsums := cumsum(x)][
+          # this calculates the total fraction by maximum value
           , tot := cumsums/max(cumsums)][
+            # actual decile calculation
             , dec := (if(decreasing) 11 - ceiling(tot * 10)
                       else ceiling(tot * 10))][
+                        # restore original order
                         order(num)][
+                          # restore original NA values or 0 to NA
                           , dec := fifelse(NA_positions, NA_real_, dec)][
+                            # return as vector
                             , dec]
   
-}
+}