stacked bar

Author: Mohammed Sadique

lib/matplotex/figure/areal/bar_chart.ex

@@ -50,6 +50,51 @@ defmodule Matplotex.Figure.Areal.BarChart do
   def materialize(figure) do
     materialize_bars(figure)
   end
+  defp materialize_bars(
+         %Figure{
+           axes:
+             %{
+               dataset: datasets,
+               data: data,
+               limit: %{x: xlim, y: ylim},
+               type: "stacked",
+               region_content: %Region{
+                 x: x_region_content,
+                 y: y_region_content,
+                 width: width_region_content,
+                 height: height_region_content
+               },
+               element: elements
+             } = axes,
+           rc_params: %RcParams{
+             x_padding: x_padding,
+             white_space: white_space,
+             concurrency: concurrency
+           }
+         } = figure
+       ) do
+        x_padding_value = width_region_content * x_padding + white_space
+        shrinked_width_region_content = width_region_content - x_padding_value * 2
+
+        bar_elements =
+          datasets
+          |> Enum.map(fn dataset ->
+            dataset
+            |> do_transform(
+              xlim,
+              ylim,
+              shrinked_width_region_content,
+              height_region_content,
+              {x_region_content + x_padding_value, y_region_content}
+            )
+            |> capture(-y_region_content, concurrency)
+          end)
+          |> List.flatten()
+
+        elements_with_bar = elements ++ bar_elements
+
+        %Figure{figure | axes: %{axes | element: elements_with_bar}}
+       end
 
   defp materialize_bars(
          %Figure{

lib/matplotex/figure/areal/plot_options.ex

@@ -36,10 +36,11 @@ defmodule Matplotex.Figure.Areal.PlotOptions do
     opts = Keyword.delete(opts, :label)
     cmap = Keyword.get(opts, :cmap)
     colors = Keyword.get(opts, :colors)
+    bottom = Keyword.get(opts, :bottom)
 
     %Figure{
       figure
-      | axes: axes |> struct(opts) |> cast_two_d_structs(opts)|> update_cmap(cmap, colors)
+      | axes: axes |> struct(opts) |> cast_two_d_structs(opts)|> update_cmap(cmap, colors) |> update_type(bottom)
     }
   end
 
@@ -63,13 +64,16 @@ defmodule Matplotex.Figure.Areal.PlotOptions do
     Keyword.drop(opts, @immutable_keys)
   end
   defp update_cmap(axes, nil, colors) when is_list(colors) do
-
     %{axes | cmap: Colormap.fetch_cmap(@default_cmap)}
   end
 
   defp update_cmap(axes, cmap, colors) when is_list(colors) do
    %{axes | cmap: Colormap.fetch_cmap(cmap)}
   end
 
-  defp update_cmap(figure, _, _), do: figure
+  defp update_cmap(axes, _, _), do: axes
+  defp update_type(axes, nil), do: axes
+  defp update_type(axes, bottom) when is_list(bottom) do
+    %{axes | type: "stacked"}
+  end
 end

lib/matplotex/figure/dataset.ex

@@ -24,7 +24,8 @@ defmodule Matplotex.Figure.Dataset do
     marker: @default_marker,
     linestyle: @default_linestyle,
     marker_size: @default_marker_size,
-    line_width: @line_width
+    line_width: @line_width,
+    bottom: nil
   ]
 
   def cast(dataset, values) do