Merge pull request #12544 from meeseeksmachine/auto-backport-of-pr-12159-on-v3.0.x

dstansby · web-flow · commit f4e07c20d901 · 2018-10-17T16:16:05.000+01:00
Backport PR #12159 on branch v3.0.x (FIX: colorbar re-check norm before draw for autolabels)
diff --git a/lib/matplotlib/colorbar.py b/lib/matplotlib/colorbar.py
@@ -241,7 +241,8 @@ def tick_values(self, vmin, vmax):
         vmin = max(vmin, self._colorbar.norm.vmin)
         vmax = min(vmax, self._colorbar.norm.vmax)
         ticks = super().tick_values(vmin, vmax)
-        return ticks[(ticks >= vmin) & (ticks <= vmax)]
+        rtol = (vmax - vmin) * 1e-10
+        return ticks[(ticks >= vmin - rtol) & (ticks <= vmax + rtol)]
 
 
 class _ColorbarAutoMinorLocator(ticker.AutoMinorLocator):
@@ -297,7 +298,10 @@ def tick_values(self, vmin, vmax):
         vmin = self._colorbar.norm.vmin
         vmax = self._colorbar.norm.vmax
         ticks = super().tick_values(vmin, vmax)
-        return ticks[(ticks >= vmin) & (ticks <= vmax)]
+        rtol = (np.log10(vmax) - np.log10(vmin)) * 1e-10
+        ticks = ticks[(np.log10(ticks) >= np.log10(vmin) - rtol) &
+              (np.log10(ticks) <= np.log10(vmax) + rtol)]
+        return ticks
 
 
 class ColorbarBase(cm.ScalarMappable):
@@ -406,7 +410,6 @@ def __init__(self, ax, cmap=None,
         else:
             self.formatter = format  # Assume it is a Formatter
         # The rest is in a method so we can recalculate when clim changes.
-        self.config_axis()
         self.draw_all()
 
     def _extend_lower(self):
@@ -440,6 +443,7 @@ def draw_all(self):
         # units:
         X, Y = self._mesh()
         C = self._values[:, np.newaxis]
+        self.config_axis()
         self._config_axes(X, Y)
         if self.filled:
             self._add_solids(X, Y, C)
@@ -594,6 +598,7 @@ def _config_axes(self, X, Y):
         ax.set_frame_on(False)
         ax.set_navigate(False)
         xy = self._outline(X, Y)
+        ax.ignore_existing_data_limits = True
         ax.update_datalim(xy)
         ax.set_xlim(*ax.dataLim.intervalx)
         ax.set_ylim(*ax.dataLim.intervaly)
@@ -1151,7 +1156,6 @@ def update_bruteforce(self, mappable):
         self.set_alpha(mappable.get_alpha())
         self.cmap = mappable.cmap
         self.norm = mappable.norm
-        self.config_axis()
         self.draw_all()
         if isinstance(self.mappable, contour.ContourSet):
             CS = self.mappable
diff --git a/lib/matplotlib/tests/test_colorbar.py b/lib/matplotlib/tests/test_colorbar.py
@@ -7,6 +7,7 @@
 from matplotlib.colors import BoundaryNorm, LogNorm, PowerNorm
 from matplotlib.cm import get_cmap
 from matplotlib.colorbar import ColorbarBase
+from matplotlib.ticker import LogLocator, LogFormatter
 
 
 def _get_cmap_norms():
@@ -411,3 +412,27 @@ def test_colorbar_log_minortick_labels():
                     r'$\mathdefault{4\times10^{4}}$']
         for l, exp in zip(lb, expected):
             assert l.get_text() == exp
+
+
+def test_colorbar_renorm():
+    x, y = np.ogrid[-4:4:31j, -4:4:31j]
+    z = 120000*np.exp(-x**2 - y**2)
+
+    fig, ax = plt.subplots()
+    im = ax.imshow(z)
+    cbar = fig.colorbar(im)
+
+    norm = LogNorm(z.min(), z.max())
+    im.set_norm(norm)
+    cbar.set_norm(norm)
+    cbar.locator = LogLocator()
+    cbar.formatter = LogFormatter()
+    cbar.update_normal(im)
+    assert np.isclose(cbar.vmin, z.min())
+
+    norm = LogNorm(z.min() * 1000, z.max() * 1000)
+    im.set_norm(norm)
+    cbar.set_norm(norm)
+    cbar.update_normal(im)
+    assert np.isclose(cbar.vmin, z.min() * 1000)
+    assert np.isclose(cbar.vmax, z.max() * 1000)
