Simplify `plot_statistics.py` code

plot_statistics.py

@@ -9,6 +9,7 @@ with open('data.json') as f:
 
 fig, targetsAxis = plt.subplots()
 fig.subplots_adjust(right = 0.8)
+axes = [targetsAxis, targetsAxis.twinx(), targetsAxis.twinx()]
 
 targets = [math.log2(target) for target in data['targets']]
 
@@ -17,38 +18,33 @@ for x, (target, nextTarget) in enumerate(zip(targets, targets[1:])):
         firstTargetDecreaseCurve = plt.axvline(x = x, color = 'purple', label = 'first target decrease')
         break
 
+targetRecomputationCurve = []
 if SHOW_TARGET_RECOMPUTATION:
     for x in range(0, len(data['targets']), 2016):
-        targetRecomputationCurve = plt.axvline(x = x, alpha = 0.1, label = 'target recomputation')
+        targetRecomputationCurve = [plt.axvline(x = x, alpha = 0.1, label = 'target recomputation')]
 
 for x, (target, nextTarget) in enumerate(zip(targets, targets[1:])):
     if nextTarget > target:
         targetIncreaseCurve = plt.axvline(x = x, alpha = 0.5, color = 'red', label = 'target increase')
 
-targetsColor = 'blue'
-targetsAxis.plot(targets, label = 'target', color = targetsColor)
-targetsAxis.set_ylabel('targets', color = targetsColor)
+axesColors = ['blue', 'green', 'brown']
+axesLabels = ['targets', 'compressed blockchain size (in blocks)', 'compressed blockchain score']
+axesYValues = [targets, data['compressSize'], data['compressScore']]
 
-compressSizeAxis = targetsAxis.twinx()
-compressScoreAxis = targetsAxis.twinx()
+for axis, color, label, yValues in zip(axes, axesColors, axesLabels, axesYValues):
+    axis.plot(yValues, color = color)
+    axis.set_ylabel(label, color = color)
 
-compressScoreAxis.spines.right.set_position(('axes', 1.15))
+axes[1].spines.right.set_position(('axes', 1.1))
 
-compressSizeColor = 'green'
-compressSizeAxis.plot(data['compressSize'], color = compressSizeColor)
-compressSizeAxis.set_ylabel('compressed blockchain size (in blocks)', color = compressSizeColor)
-
-compressScoreColor = 'brown'
-compressScoreAxis.plot(data['compressScore'], color = compressScoreColor)
-compressScoreAxis.set_ylabel('compressed blockchain score', color = compressScoreColor)
-
-curves = ([targetRecomputationCurve] if SHOW_TARGET_RECOMPUTATION else []) + [firstTargetDecreaseCurve] + [targetIncreaseCurve]
+curves = targetRecomputationCurve + [firstTargetDecreaseCurve] + [targetIncreaseCurve]
 labels = [curve.get_label() for curve in curves]
+
 plt.legend(curves, labels, loc='upper center', framealpha=1)
 
 ax1.set_xlabel('Block height')
 
-for ax, color in zip([targetsAxis, compressSizeAxis, compressScoreAxis], [targetsColor, compressSizeColor, compressScoreColor]):
+for ax, color in zip(axes, axesColors):
     ax.tick_params(axis='y', colors=color)
 
 plt.title('Variable difficulty Bitcoin compressed blockchain evolution')