Extend color legend size for scatter charts for matplotlib (#286)

* rec series

* rec

* add changes back

* fix tests

* rm

* change

* set plotting_style

* nice

* black

* rm

* change rec

* reuse export

* change size of plot

* rm

* ref

* fixed

* reform

* enlarge font

* enlarge font

Co-authored-by: Caitlyn Chen <caitlynachen@berkeley.edu>

lux/vislib/matplotlib/ScatterChart.py

@@ -53,18 +53,20 @@ def initialize_chart(self):
         x_pts = df[x_attr.attribute]
         y_pts = df[y_attr.attribute]
 
+        set_fig_code = ""
         plot_code = ""
 
         color_attr = self.vis.get_attr_by_channel("color")
         if len(color_attr) == 1:
-            self.fig, self.ax = matplotlib_setup(6, 5)
             color_attr_name = color_attr[0].attribute
             color_attr_type = color_attr[0].data_type
             colors = df[color_attr_name].values
             plot_code += f"colors = df['{color_attr_name}'].values\n"
             unique = list(set(colors))
             vals = [unique.index(i) for i in colors]
             if color_attr_type == "quantitative":
+                self.fig, self.ax = matplotlib_setup(7, 5)
+                set_fig_code = "fig, ax = plt.subplots(7, 5)\n"
                 self.ax.scatter(x_pts, y_pts, c=vals, cmap="Blues", alpha=0.5)
                 plot_code += f"ax.scatter(x_pts, y_pts, c={vals}, cmap='Blues', alpha=0.5)\n"
                 my_cmap = plt.cm.get_cmap("Blues")
@@ -82,10 +84,29 @@ def initialize_chart(self):
                 plot_code += f"cbar = plt.colorbar(sm, label='{color_attr_name}')\n"
                 plot_code += f"cbar.outline.set_linewidth(0)\n"
             else:
-                scatter = self.ax.scatter(x_pts, y_pts, c=vals, cmap="Set1")
-                plot_code += f"scatter = ax.scatter(x_pts, y_pts, c={vals}, cmap='Set1')\n"
+                if len(unique) >= 16:
+                    unique = unique[:16]
+
+                maxlen = 0
+                for i in range(len(unique)):
+                    unique[i] = str(unique[i])
+                    if len(unique[i]) > 26:
+                        unique[i] = unique[i][:26] + "..."
+                    if len(unique[i]) > maxlen:
+                        maxlen = len(unique[i])
+                if maxlen > 20:
+                    self.fig, self.ax = matplotlib_setup(9, 5)
+                    set_fig_code = "fig, ax = plt.subplots(9, 5)\n"
+                else:
+                    self.fig, self.ax = matplotlib_setup(7, 5)
+                    set_fig_code = "fig, ax = plt.subplots(7, 5)\n"
+
+                cmap = "Set1"
+                if len(unique) > 9:
+                    cmap = "tab20c"
+                scatter = self.ax.scatter(x_pts, y_pts, c=vals, cmap=cmap)
+                plot_code += f"scatter = ax.scatter(x_pts, y_pts, c={vals}, cmap={cmap})\n"
 
-                unique = [str(i) for i in unique]
                 leg = self.ax.legend(
                     handles=scatter.legend_elements(num=range(0, len(unique)))[0],
                     labels=unique,
@@ -95,6 +116,7 @@ def initialize_chart(self):
                     loc="upper left",
                     ncol=1,
                     frameon=False,
+                    fontsize="13",
                 )
                 scatter.set_alpha(0.5)
                 plot_code += f"""ax.legend(
@@ -105,23 +127,24 @@ def initialize_chart(self):
                     bbox_to_anchor=(1.05, 1), 
                     loc='upper left', 
                     ncol=1, 
-                    frameon=False,)\n"""
+                    frameon=False,
+                    fontsize='13')\n"""
                 plot_code += "scatter.set_alpha(0.5)\n"
         else:
+            set_fig_code = "fig, ax = plt.subplots(4.5, 4)\n"
             self.ax.scatter(x_pts, y_pts, alpha=0.5)
             plot_code += f"ax.scatter(x_pts, y_pts, alpha=0.5)\n"
-
-        self.ax.set_xlabel(x_attr_abv)
-        self.ax.set_ylabel(y_attr_abv)
+        self.ax.set_xlabel(x_attr_abv, fontsize="15")
+        self.ax.set_ylabel(y_attr_abv, fontsize="15")
 
         self.code += "import numpy as np\n"
         self.code += "from math import nan\n"
         self.code += "from matplotlib.cm import ScalarMappable\n"
 
-        self.code += f"fig, ax = plt.subplots()\n"
+        self.code += set_fig_code
         self.code += f"x_pts = df['{x_attr.attribute}']\n"
         self.code += f"y_pts = df['{y_attr.attribute}']\n"
 
         self.code += plot_code
-        self.code += f"ax.set_xlabel('{x_attr_abv}')\n"
-        self.code += f"ax.set_ylabel('{y_attr_abv}')\n"
+        self.code += f"ax.set_xlabel('{x_attr_abv}', fontsize='15')\n"
+        self.code += f"ax.set_ylabel('{y_attr_abv}', fontsize='15')\n"