Rework of the comparison plot

app.py

@@ -12,6 +12,7 @@ import seaborn as sns
 import matplotlib.pyplot as plt
 from datasets import load_dataset
 from scipy.special import expit
+from matplotlib.ticker import FixedLocator, StrMethodFormatter
 
 from hdinterval import HDI, HDInterval
 
@@ -134,12 +135,6 @@ class RankPlotter(DataPlotter):
 class ComparisonPlotter(DataPlotter):
     _uncertain = 0.5
 
-    @staticmethod
-    def to_relative(hdi, ax):
-        (lhs, rhs) = ax.get_xlim()
-        length = rhs - lhs
-        yield from (abs(lhs - x) / length for x in hdi)
-
     def __init__(self, df, model_1, model_2, ci):
         super().__init__(compare(df, model_1, model_2))
         self.interval = HDInterval(self.df)
@@ -147,41 +142,49 @@ class ComparisonPlotter(DataPlotter):
 
     def draw(self, ax):
         hdi = self.interval(self.ci)
+        (c_hist, c_hdi) = sns.color_palette('colorblind', n_colors=2)
 
-        ax = sns.histplot(self.df, stat='density')
-
-        top = max(x.get_height() for x in ax.patches)
-        y = top * 1.05
-
-        (_, color, *_) = sns.color_palette()
-        (xmin, xmax) = self.to_relative(hdi, ax)
-        linestyle = 'dashed' if self._uncertain in hdi else 'solid'
-        ax.axhline(y=y,
-                   xmin=xmin,
-                   xmax=xmax,
-                   linestyle=linestyle,
-                   color=color)
-        ax.set_xlabel('Pr(M$_{1}$ \u003E M$_{2}$)')
-
-        x = (hdi.lower + hdi.upper) / 2
-        ax.text(x=x,
-                y=y,
-                s=f'{self.ci:.0%} HDI',
-                backgroundcolor='white',
-                horizontalalignment='center',
-                verticalalignment='center')
+        ax = sns.histplot(data=self.df,
+                          stat='density',
+                          color=c_hist)
+        ax.set_xlabel('logit$^{-1}$(\u03B1$_{1}$ - \u03B1$_{2}$)')
 
+        self.pr(ax, hdi, c_hdi)
         try:
             ci_min = self.interval.at(self._uncertain)
-            ax.text(x=0.01,
-                    y=0.99,
-                    s=f'0.5 \u2248\u2208 {ci_min:.0%} HDI',
+            ax.text(x=0.025,
+                    y=0.975,
+                    s=f'{self._uncertain} \u2208 {ci_min:.0%} HDI',
+                    fontsize='small',
+                    fontstyle='italic',
                     horizontalalignment='left',
                     verticalalignment='top',
                     transform=ax.transAxes)
         except ArithmeticError:
             pass
 
+    def pr(self, ax, hdi, color):
+        x = self.df.median()
+        zorder = ax.zorder - 1
+
+        (label, *_) = ax.get_xticklabels()
+        parts = label.get_text().split('.')
+        decimals = len(parts[-1]) + 1 if parts else 2
+        fmt = f'Pr(M$_{{{{1}}}}$ \u003E M$_{{{{2}}}}$) = {{x:.{decimals}f}}'
+
+        ax.axvline(x=x,
+                   color=color,
+                   linestyle='dashed')
+        ax.axvspan(xmin=hdi.lower,
+                   xmax=hdi.upper,
+                   alpha=0.15,
+                   color=color,
+                   zorder=zorder)
+
+        ax_ = ax.secondary_xaxis('top')
+        ax_.xaxis.set_major_locator(FixedLocator([x]))
+        ax_.xaxis.set_major_formatter(StrMethodFormatter(fmt))
+
 #
 #
 #
@@ -258,17 +261,17 @@ def layout(tab):
 
         with gr.Row():
             with gr.Column():
-                gr.Markdown('''
+                gr.Markdown(f'''
 
                 Probability that Model 1 is preferred to Model 2. The
                 histogram is represents the distribution of inverse
-                logit of the difference in model abilities. The
-                horizontal line above the histogram marks the chosen
-                [highest density
-                interval](https://cran.r-project.org/package=HDInterval). The
-                line is dashed if the interval overlaps 0.5, solid
-                otherwise. The HDI in the upper left denotes the
-                smallest approximate HDI that is inclusive of 0.5.
+                logit of the difference in model abilities. The dashed
+                vertical line is its median. The shaded region
+                demarcates the chosen [highest density
+                interval](https://cran.r-project.org/package=HDInterval)
+                (HDI). The note in the upper left denotes the smallest
+                HDI that is inclusive of
+                {ComparisonPlotter._uncertain}.
 
                 ''')
             with gr.Column():