Replace sortperm by alternative pattern

docs/Project.toml

@@ -4,6 +4,7 @@ DataFrames = "a93c6f00-e57d-5684-b7b6-d8193f3e46c0"
 DataFramesMeta = "1313f7d8-7da2-5740-9ea0-a2ca25f37964"
 Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
 HTTP = "cd3eb016-35fb-5094-929b-558a96fad6f3"
+StatsBase = "2913bbd2-ae8a-5f71-8c99-4fb6c76f3a91"
 
 [compat]
 Documenter = "0.27"

docs/src/dplyr.md

@@ -256,19 +256,33 @@ Same as above, except here we filter the rows for mammals that sleep for 16 or m
 end
 ```
 
-Something slightly more complicated: same as above, except arrange the rows in the `:sleep_total` column in a descending order. For this, use the function `sortperm` with the keyword argument `rev=true`.
+Something slightly more complicated: same as above, except arrange the rows in the `:sleep_total` column in a descending order. Since this column is numeric we can do it by negating it:
 
 ```@repl 1
 @chain msleep begin 
     @select :name :order :sleep_total
     @orderby begin 
-        :order 
-        sortperm(:sleep_total, rev=true)
+        :order
+        -:sleep_total
     end 
     @rsubset :sleep_total >= 16
 end
 ```
 
+Alternatively, using the StatsBase.jl package you could have written `ordinalrank(:sleep_total, rev=true)`.
+Finally, if you wanted to avoid using an additional package you could use the following expression `invperm(sortperm(:sleep_total, rev=true))`.
+
+Here is a minimal example of sorting string column in reverse:
+
+```@repl 1
+using StatsBase
+df = DataFrame(group=[1, 2, 1, 2, 1], name = ["Bob", "Dexter", "Alice", "Eve", "Cedric"])
+@orderby df begin
+    :group
+    ordinalrank(:name, rev=true)
+end
+```
+
 ## Create New Columns Using `@transform` and `@rtransform`
 
 The `@transform` macro will add new columns to the data frame. Like with other macros, use `@rtransform` to operate row-wise. Create a new column called `:rem_proportion`, which is the ratio of rem sleep to total amount of sleep. 

src/macros.jl

@@ -1214,38 +1214,38 @@ $ASTABLE_RHS_ORDERBY_DOCS
 julia> using DataFramesMeta, Statistics
 
 julia> d = DataFrame(x = [3, 3, 3, 2, 1, 1, 1, 2, 1, 1], n = 1:10,
-                     c = ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j"]);
+                     c = ["a", "c", "b", "e", "d", "g", "f", "i", "j", "h"]);
 
-julia> @orderby(d, -1 .* :n)
+julia> @orderby(d, -:n)
 10×3 DataFrame
  Row │ x      n      c
      │ Int64  Int64  String
 ─────┼──────────────────────
-   1 │     1     10  j
-   2 │     1      9  i
-   3 │     2      8  h
-   4 │     1      7  g
-   5 │     1      6  f
-   6 │     1      5  e
-   7 │     2      4  d
-   8 │     3      3  c
-   9 │     3      2  b
+   1 │     1     10  h
+   2 │     1      9  j
+   3 │     2      8  i
+   4 │     1      7  f
+   5 │     1      6  g
+   6 │     1      5  d
+   7 │     2      4  e
+   8 │     3      3  b
+   9 │     3      2  c
   10 │     3      1  a
 
-julia> @orderby(d, sortperm(:c, rev = true))
+julia> @orderby(d, invperm(sortperm(:c, rev = true)))
 10×3 DataFrame
  Row │ x      n      c
      │ Int64  Int64  String
 ─────┼──────────────────────
-   1 │     1     10  j
-   2 │     1      9  i
-   3 │     2      8  h
-   4 │     1      7  g
-   5 │     1      6  f
-   6 │     1      5  e
-   7 │     2      4  d
-   8 │     3      3  c
-   9 │     3      2  b
+   1 │     1      9  j
+   2 │     2      8  i
+   3 │     1     10  h
+   4 │     1      6  g
+   5 │     1      7  f
+   6 │     2      4  e
+   7 │     1      5  d
+   8 │     3      2  c
+   9 │     3      3  b
   10 │     3      1  a
 
 julia> @orderby d begin