FIX: LogFormatter minor ticks with minor_thresholds of (0,0) misbehaves

Yi Wei · Yi Wei · commit 6bbe1a48700a · 2023-07-10T08:34:24.000+02:00
fix test failures
diff --git a/lib/matplotlib/tests/test_ticker.py b/lib/matplotlib/tests/test_ticker.py
@@ -1,3 +1,4 @@
+import math
 from contextlib import nullcontext
 import itertools
 import locale
@@ -1141,6 +1142,15 @@ def _sub_labels(self, axis, subs=()):
         label_test = [fmt(x) != '' for x in minor_tlocs]
         assert label_test == label_expected
 
+    def _only_base_labels(self, axis):
+        fmt = axis.get_minor_formatter()
+        minor_tlocs = axis.get_minorticklocs()
+        fmt.set_locs(minor_tlocs)
+        fxs = np.log(minor_tlocs)/np.log(10)
+        label_expected = [math.isclose(fx, round(fx)) for fx in fxs]
+        label_test = [fmt(x) != '' for x in minor_tlocs]
+        assert label_test == label_expected
+
     @mpl.style.context('default')
     def test_sublabel(self):
         # test label locator
@@ -1179,6 +1189,15 @@ def test_sublabel(self):
         ax.set_xlim(0.5, 0.9)
         self._sub_labels(ax.xaxis, subs=np.arange(2, 10, dtype=int))
 
+        # minor_thresholds=(0, 0), label only bases
+        ax.xaxis.set_minor_formatter(
+            mticker.LogFormatter(
+                labelOnlyBase=False,
+                minor_thresholds=(0, 0)
+            )
+        )
+        self._only_base_labels(ax.xaxis)
+
     @pytest.mark.parametrize('val', [1, 10, 100, 1000])
     def test_LogFormatter_call(self, val):
         # test _num_to_string method used in __call__
diff --git a/lib/matplotlib/ticker.py b/lib/matplotlib/ticker.py
@@ -950,7 +950,7 @@ def set_locs(self, locs=None):
 
         if numdec > self.minor_thresholds[0]:
             # Label only bases
-            self._sublabels = {1}
+            self._sublabels = {}
         elif numdec > self.minor_thresholds[1]:
             # Add labels between bases at log-spaced coefficients;
             # include base powers in case the locations include
@@ -984,9 +984,11 @@ def __call__(self, x, pos=None):
         exponent = round(fx) if is_x_decade else np.floor(fx)
         coeff = round(b ** (fx - exponent))
 
-        if self.labelOnlyBase and not is_x_decade:
-            return ''
-        if self._sublabels is not None and coeff not in self._sublabels:
+        # Label only bases
+        if self.labelOnlyBase or self._sublabels == {}:
+            if not is_x_decade:
+                return ''
+        elif self._sublabels is not None and coeff not in self._sublabels:
             return ''
 
         vmin, vmax = self.axis.get_view_interval()
@@ -1070,9 +1072,11 @@ def __call__(self, x, pos=None):
         if is_x_decade:
             fx = round(fx)
 
-        if self.labelOnlyBase and not is_x_decade:
-            return ''
-        if self._sublabels is not None and coeff not in self._sublabels:
+        # Label only bases
+        if self.labelOnlyBase or self._sublabels == {}:
+            if not is_x_decade:
+                return ''
+        elif self._sublabels is not None and coeff not in self._sublabels:
             return ''
 
         # use string formatting of the base if it is not an integer
