Implement dynamic fonts for heatmap

kavian/eda/plot.py

@@ -205,21 +205,35 @@ def heatmap(dataframe, palette='kavian', subset=None):
 
     numerical = dataframe.select_dtypes(NUM)
     corr = numerical.corr()
-    font_size = 18 - len(numerical.columns)
 
-    annot_kws = {'size': font_size, 'fontweight': 'bold', 'fontstyle': 'italic'}
+    font_size = 18 - len(numerical.columns)
+    font_size = 8 if font_size < 8 else font_size
     cbar_kws = {'pad': 0.01}
 
     if palette == 'kavian':
         palette = sns.diverging_palette(18, 240, s=80, l=50, n=19, center="dark")
 
-    sns.heatmap(corr, ax=ax, cmap=palette, annot=True, annot_kws=annot_kws,
-                cbar_kws=cbar_kws, fmt='.2f', linecolor='black', linewidth=0.5, square=True)
+    too_many_cols = len(numerical.columns) >= 12
+
+    # Too many values for annotations to be legible
+    if too_many_cols:
+        sns.heatmap(corr, ax=ax, cmap=palette, cbar_kws=cbar_kws,
+                    fmt='.2f', linecolor='black', linewidth=0.5, square=True)
+
+    else:
+        annot_kws = {'size': font_size, 'fontweight': 'bold', 'fontstyle': 'italic'}
+        sns.heatmap(corr, ax=ax, cmap=palette, annot=True, annot_kws=annot_kws,
+                    cbar_kws=cbar_kws, fmt='.2f', linecolor='black', linewidth=0.5, square=True)
+
+    xticklabels = '' if too_many_cols else ax.get_xticklabels()
 
     ax.tick_params(rotation=20)
-    ax.set_xticklabels(ax.get_xticklabels(), fontweight='bold', fontstyle='italic')
-    ax.set_yticklabels(ax.get_yticklabels(), fontweight='bold', fontstyle='italic')
+    ax.set_xticklabels(xticklabels, fontweight='bold', fontstyle='italic', fontsize=font_size)
+    ax.set_yticklabels(ax.get_yticklabels(), fontweight='bold', fontstyle='italic', fontsize=font_size)
     ax.set_title(f'EDA Heatmap', fontdict={'fontsize': 24, 'fontfamily': 'serif'})
 
     plt.tight_layout()
     plt.show()
+
+
+