FIX: allow flipped

jklymak · jklymak · commit 18bf9770a6f0 · 2018-09-30T09:58:19.000-07:00
diff --git a/lib/matplotlib/projections/polar.py b/lib/matplotlib/projections/polar.py
@@ -58,7 +58,8 @@ def transform_non_affine(self, tr):
             t += self._axis.get_theta_offset()
 
         if self._use_rmin and self._axis is not None:
-            r = r - self._axis.get_rorigin()
+            r = (r - self._axis.get_rorigin()) * self._axis.get_rsign()
+
         mask = r < 0
         x[:] = np.where(mask, np.nan, r * np.cos(t))
         y[:] = np.where(mask, np.nan, r * np.sin(t))
@@ -169,6 +170,7 @@ def transform_non_affine(self, xy):
 
         if self._use_rmin and self._axis is not None:
             r += self._axis.get_rorigin()
+            r *= self._axis.get_rsign()
 
         return np.concatenate((theta, r), 1)
     transform_non_affine.__doc__ = \
@@ -432,10 +434,9 @@ def __call__(self):
         # Ensure previous behaviour with full circle non-annular views.
         if self._axes:
             if _is_full_circle_rad(*self._axes.viewLim.intervalx):
-                rorigin = self._axes.get_rorigin()
+                rorigin = self._axes.get_rorigin() * self._axes.get_rsign()
                 if self._axes.get_rmin() <= rorigin:
                     show_all = False
-
         if show_all:
             return self.base()
         else:
@@ -455,7 +456,7 @@ def refresh(self):
 
     def view_limits(self, vmin, vmax):
         vmin, vmax = self.base.view_limits(vmin, vmax)
-        return mtransforms.nonsingular(min(0, vmin), vmax)
+        return mtransforms.nonsingular(vmin, vmax)
 
 
 class _ThetaShift(mtransforms.ScaledTranslation):
@@ -790,7 +791,6 @@ def __str__(self):
     def get_points(self):
         if self._invalid:
             points = self._viewLim.get_points().copy()
-
             # Scale angular limits to work with Wedge.
             points[:, 0] *= 180 / np.pi
             if points[0, 0] > points[1, 0]:
@@ -1015,8 +1015,8 @@ def draw(self, *args, **kwargs):
         thetamin, thetamax = np.rad2deg(self._realViewLim.intervalx)
         if thetamin > thetamax:
             thetamin, thetamax = thetamax, thetamin
-        rmin, rmax = self._realViewLim.intervaly - self.get_rorigin()
-
+        rmin, rmax = ((self._realViewLim.intervaly - self.get_rorigin()) *
+                        self.get_rsign())
         if isinstance(self.patch, mpatches.Wedge):
             # Backwards-compatibility: Any subclassed Axes might override the
             # patch to not be the Wedge that PolarAxes uses.
@@ -1183,6 +1183,10 @@ def set_rorigin(self, rorigin):
     def get_rorigin(self):
         return self._originViewLim.y0
 
+    def get_rsign(self):
+        return np.sign(self._originViewLim.y1 - self._originViewLim.y0)
+
+
     def set_rlim(self, bottom=None, top=None, emit=True, auto=False, **kwargs):
         """
         See `~.polar.PolarAxes.set_ylim`.
@@ -1259,9 +1263,6 @@ def set_ylim(self, bottom=None, top=None, emit=True, auto=False,
         if top is None and len(bottom) == 2:
             top = bottom[1]
             bottom = bottom[0]
-        if bottom >= top:
-            raise ValueError('Polar axes y/r-limits must be increasing; '
-                             'i.e. bottom < top')
 
         return super().set_ylim(bottom=bottom, top=top, emit=emit, auto=auto)
 
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -735,6 +735,23 @@ def test_polar_rorigin():
     ax.set_rorigin(0.0)
 
 
+@image_comparison(baseline_images=['polar_invertedylim'], style='default',
+                   extensions=['png'])
+def test_polar_invertedylim():
+    fig = plt.figure()
+    ax = fig.add_axes([0.1, 0.1, 0.8, 0.8], polar=True)
+    ax.set_ylim(2, 0)
+
+
+@image_comparison(baseline_images=['polar_invertedylim_rorigin'],
+                  style='default', extensions=['png'])
+def test_polar_invertedylim_rorigin():
+    fig = plt.figure()
+    ax = fig.add_axes([0.1, 0.1, 0.8, 0.8], polar=True)
+    ax.set_ylim(2, 0)
+    ax.set_rorigin(3)
+
+
 @image_comparison(baseline_images=['polar_theta_position'], style='default')
 def test_polar_theta_position():
     r = np.arange(0, 3.0, 0.01)
@@ -747,13 +764,6 @@ def test_polar_theta_position():
     ax.set_theta_direction('clockwise')
 
 
-def test_polar_invertedylim():
-    fig = plt.figure()
-    ax = fig.add_axes([0.1, 0.1, 0.8, 0.8], polar=True)
-    with pytest.raises(ValueError):
-        ax.set_ylim(90, -45)
-    with pytest.raises(ValueError):
-        ax.set_rlim(90, -45)
 
 
 @image_comparison(baseline_images=['polar_rlabel_position'], style='default')
