Fixing compiler warnings and typo (#1159)

Author: akoutmos

lib/explorer/backend/lazy_series.ex

@@ -822,9 +822,7 @@ defmodule Explorer.Backend.LazySeries do
        when op in [:first, :last, :sum, :min, :max, :product],
        do: series.dtype
 
-  defp dtype_for_agg_operation(op, _) when op in [:all?, :any?], do: :boolean
   defp dtype_for_agg_operation(:mode, series), do: {:list, series.dtype}
-
   defp dtype_for_agg_operation(_, _), do: {:f, 64}
 
   defp resolve_numeric_dtype(items) do
@@ -1077,13 +1075,6 @@ defmodule Explorer.Backend.LazySeries do
 
   defp to_elixir_ast(other), do: other
 
-  @impl true
-  def size(series) do
-    data = new(:size, [lazy_series!(series)], {:u, 32})
-
-    Backend.Series.new(data, {:u, 32})
-  end
-
   @impl true
   def transform(_series, _fun) do
     raise """

lib/explorer/polars_backend/expression.ex

@@ -322,7 +322,7 @@ defmodule Explorer.PolarsBackend.Expression do
     Native.expr_int_range(to_expr(0), size_expr, 1, {:u, 32})
   end
 
-  for {op, arity} <- @all_expressions do
+  for {op, arity} <- @all_expressions -- @first_only_expressions do
     args = Macro.generate_arguments(arity, __MODULE__)
 
     updates =

lib/explorer/series.ex

@@ -1143,7 +1143,7 @@ defmodule Explorer.Series do
     do: apply_series(series, :strftime, [format_string])
 
   def strftime(%Series{dtype: dtype}, _format_string),
-    do: dtype_error("strftime/2", dtype, :datetime_like)
+    do: dtype_error("strftime/2", dtype, [:datetime_like])
 
   @doc """
   Clip (or clamp) the values in a series.
@@ -5346,15 +5346,15 @@ defmodule Explorer.Series do
 
     float_series =
       case dtype(series) do
-        :f32 ->
+        {:f, 32} ->
           series
 
-        :f64 ->
+        {:f, 64} ->
           series
 
         _ ->
           try do
-            cast(series, :f64)
+            cast(series, {:f, 64})
           rescue
             _ ->
               raise ArgumentError,

notebooks/exploring_explorer.livemd

@@ -800,7 +800,7 @@ In `Explorer`, like in `dplyr`, we have five main verbs to work with dataframes:
 - sort
 - summarise
 
-We are going to explore then in this notebook, but first we need to "require"
+We are going to explore them in this notebook, but first we need to "require"
 the `Explorer.DataFrame` module in order to load the macros needed for these verbs.
 
 I want to take the opportunity to create a shorter alias for the `DataFrame` module,

test/explorer/series_test.exs

@@ -4658,7 +4658,7 @@ defmodule Explorer.SeriesTest do
   end
 
   describe "ewm_mean/2" do
-    test "returns calculated ewm values with default options used for calculation" do
+    test "returns calculated ewm values with default options used for integer calculation" do
       s1 = 1..10 |> Enum.to_list() |> Series.from_list()
       s2 = Series.ewm_mean(s1)
 
@@ -4676,6 +4676,24 @@ defmodule Explorer.SeriesTest do
              ])
     end
 
+    test "returns calculated ewm values with default options used for f64 calculation" do
+      s1 = Series.from_list([1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0])
+      s2 = Series.ewm_mean(s1)
+
+      assert all_close?(s2, [
+               1.0,
+               1.6666666666666667,
+               2.4285714285714284,
+               3.2666666666666666,
+               4.161290322580645,
+               5.095238095238095,
+               6.05511811023622,
+               7.031372549019608,
+               8.017612524461839,
+               9.009775171065494
+             ])
+    end
+
     test "returns calculated ewma with differernt smoothing factor if different alpha is passed" do
       s1 = 1..10 |> Enum.to_list() |> Series.from_list()
       s2 = Series.ewm_mean(s1, alpha: 0.8)