More precise choice of axes limits.

plt.plot([-.1, .2]) used to pick (in round numbers mode) [-.1, .25] as ylims due to floating point inaccuracies; change it to pick [-.1, .2] (up to floating point inaccuracies). Support for the (unused and deprecated-in-comment) "trim" keyword argument has been dropped as the way ticks are picked has changed. Many test images have changed! Implementation notes: - A bug in numpy's implementation of divmod (numpy/numpy#6127) is worked around. - The implementation of scale_range has also been cleaned. See #5767, #5738.
matplotlib · tacaswell · Mar 20, 2016 · Dec 30, 2015 · Mar 20, 2016 · 6d23c8e675fd9a8287d2b951ec69d5d432691ece
commit 6d23c8e675fd9a8287d2b951ec69d5d432691ece
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/autoscale_tiny_range.pdf b/lib/matplotlib/tests/baseline_images/test_axes/autoscale_tiny_range.pdf
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/autoscale_tiny_range.png b/lib/matplotlib/tests/baseline_images/test_axes/autoscale_tiny_range.png
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/autoscale_tiny_range.svg b/lib/matplotlib/tests/baseline_images/test_axes/autoscale_tiny_range.svg
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/bar_tick_label_single.png b/lib/matplotlib/tests/baseline_images/test_axes/bar_tick_label_single.png
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/errorbar_mixed.pdf b/lib/matplotlib/tests/baseline_images/test_axes/errorbar_mixed.pdf
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/errorbar_mixed.svg b/lib/matplotlib/tests/baseline_images/test_axes/errorbar_mixed.svg
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/formatter_large_small.pdf b/lib/matplotlib/tests/baseline_images/test_axes/formatter_large_small.pdf
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/formatter_large_small.png b/lib/matplotlib/tests/baseline_images/test_axes/formatter_large_small.png
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/formatter_large_small.svg b/lib/matplotlib/tests/baseline_images/test_axes/formatter_large_small.svg
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/twin_spines_on_top.png b/lib/matplotlib/tests/baseline_images/test_axes/twin_spines_on_top.png
diff --git a/lib/matplotlib/tests/baseline_images/test_bbox_tight/bbox_inches_tight_raster.pdf b/lib/matplotlib/tests/baseline_images/test_bbox_tight/bbox_inches_tight_raster.pdf
diff --git a/lib/matplotlib/tests/baseline_images/test_bbox_tight/bbox_inches_tight_raster.png b/lib/matplotlib/tests/baseline_images/test_bbox_tight/bbox_inches_tight_raster.png
diff --git a/lib/matplotlib/tests/baseline_images/test_bbox_tight/bbox_inches_tight_raster.svg b/lib/matplotlib/tests/baseline_images/test_bbox_tight/bbox_inches_tight_raster.svg
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -24,7 +24,7 @@
 from matplotlib.testing.decorators import image_comparison, cleanup
 import matplotlib.pyplot as plt
 import matplotlib.markers as mmarkers
-from numpy.testing import assert_array_equal
+from numpy.testing import assert_allclose, assert_array_equal
 import warnings
 from matplotlib.cbook import IgnoredKeywordWarning

@@ -3725,8 +3725,7 @@ def test_vline_limit():
    ax.axvline(0.5)
    ax.plot([-0.1, 0, 0.2, 0.1])
    (ymin, ymax) = ax.get_ylim()
-    assert ymin == -0.1
-    assert ymax == 0.25
+    assert_allclose(ax.get_ylim(), (-.1, .2))


 @cleanup

diff --git a/lib/matplotlib/ticker.py b/lib/matplotlib/ticker.py
@@ -161,13 +161,23 @@
 from matplotlib import rcParams
 from matplotlib import cbook
 from matplotlib import transforms as mtransforms
+from matplotlib.cbook import mplDeprecation

 import warnings

 if six.PY3:
    long = int


+# Work around numpy/numpy#6127.
+def _divmod(x, y):
+    if isinstance(x, np.generic):
+        x = x.item()
+    if isinstance(y, np.generic):
+        y = y.item()
+    return six.moves.builtins.divmod(x, y)
+
+
 def _mathdefault(s):
    """
    For backward compatibility, in classic mode we display
@@ -1221,7 +1231,7 @@ def view_limits(self, vmin, vmax):
            vmax += 1

        if rcParams['axes.autolimit_mode'] == 'round_numbers':
-            exponent, remainder = divmod(math.log10(vmax - vmin), 1)
+            exponent, remainder = _divmod(math.log10(vmax - vmin), 1)
            if remainder < 0.5:
                exponent -= 1
            scale = 10 ** (-exponent)
@@ -1247,30 +1257,30 @@ def __init__(self, base):

    def lt(self, x):
        'return the largest multiple of base < x'
-        d, m = divmod(x, self._base)
+        d, m = _divmod(x, self._base)
        if closeto(m, 0) and not closeto(m / self._base, 1):
            return (d - 1) * self._base
        return d * self._base

    def le(self, x):
        'return the largest multiple of base <= x'
-        d, m = divmod(x, self._base)
+        d, m = _divmod(x, self._base)
        if closeto(m / self._base, 1):  # was closeto(m, self._base)
            #looks like floating point error
            return (d + 1) * self._base
        return d * self._base

    def gt(self, x):
        'return the smallest multiple of base > x'
-        d, m = divmod(x, self._base)
+        d, m = _divmod(x, self._base)
        if closeto(m / self._base, 1):
            #looks like floating point error
            return (d + 2) * self._base
        return (d + 1) * self._base

    def ge(self, x):
        'return the smallest multiple of base >= x'
-        d, m = divmod(x, self._base)
+        d, m = _divmod(x, self._base)
        if closeto(m, 0) and not closeto(m / self._base, 1):
            return d * self._base
        return (d + 1) * self._base
@@ -1326,23 +1336,13 @@ def view_limits(self, dmin, dmax):


 def scale_range(vmin, vmax, n=1, threshold=100):
-    dv = abs(vmax - vmin)
-    if dv == 0:     # maxabsv == 0 is a special case of this.
-        return 1.0, 0.0
-        # Note: this should never occur because
-        # vmin, vmax should have been checked by nonsingular(),
-        # and spread apart if necessary.
-    meanv = 0.5 * (vmax + vmin)
+    dv = abs(vmax - vmin)  # > 0 as nonsingular is called before.
+    meanv = (vmax + vmin) / 2
    if abs(meanv) / dv < threshold:
        offset = 0
-    elif meanv > 0:
-        ex = divmod(math.log10(meanv), 1)[0]
-        offset = 10 ** ex
    else:
-        ex = divmod(math.log10(-meanv), 1)[0]
-        offset = -10 ** ex
-    ex = divmod(math.log10(dv / n), 1)[0]
-    scale = 10 ** ex
+        offset = math.copysign(10 ** (math.log10(abs(meanv)) // 1), meanv)
+    scale = 10 ** (math.log10(dv / n) // 1)
    return scale, offset


@@ -1352,7 +1352,6 @@ class MaxNLocator(Locator):
    """
    default_params = dict(nbins=10,
                          steps=None,
-                          trim=True,
                          integer=False,
                          symmetric=False,
                          prune=None)
@@ -1388,9 +1387,6 @@ def __init__(self, *args, **kwargs):
            will be removed.  If prune==None, no ticks will be removed.

        """
-        # I left "trim" out; it defaults to True, and it is not
-        # clear that there is any use case for False, so we may
-        # want to remove that kwarg.  EF 2010/04/18
        if args:
            kwargs['nbins'] = args[0]
            if len(args) > 1:
@@ -1406,7 +1402,9 @@ def set_params(self, **kwargs):
            if self._nbins != 'auto':
                self._nbins = int(self._nbins)
        if 'trim' in kwargs:
-            self._trim = kwargs['trim']
+            warnings.warn(
+                "The 'trim' keyword has no effect since version 2.0.",
+                mplDeprecation)
        if 'integer' in kwargs:
            self._integer = kwargs['integer']
        if 'symmetric' in kwargs:
@@ -1429,9 +1427,9 @@ def set_params(self, **kwargs):
        if 'integer' in kwargs:
            self._integer = kwargs['integer']
        if self._integer:
-            self._steps = [n for n in self._steps if divmod(n, 1)[1] < 0.001]
+            self._steps = [n for n in self._steps if _divmod(n, 1)[1] < 0.001]

-    def bin_boundaries(self, vmin, vmax):
+    def _raw_ticks(self, vmin, vmax):
        nbins = self._nbins
        if nbins == 'auto':
            nbins = max(min(self.axis.get_tick_space(), 9), 1)
@@ -1449,23 +1447,30 @@ def bin_boundaries(self, vmin, vmax):
            if step < scaled_raw_step:
                continue
            step *= scale
-            best_vmin = step * divmod(vmin, step)[0]
+            best_vmin = vmin // step * step
            best_vmax = best_vmin + step * nbins
-            if (best_vmax >= vmax):
+            if best_vmax >= vmax:
                break
-        if self._trim:
-            extra_bins = int(divmod((best_vmax - vmax), step)[0])
-            nbins -= extra_bins
-        return (np.arange(nbins + 1) * step + best_vmin + offset)
+
+        # More than nbins may be required, e.g. vmin, vmax = -4.1, 4.1 gives
+        # nbins=9 but 10 bins are actually required after rounding.  So we just
+        # create the bins that span the range we need instead.
+        low = round(Base(step).le(vmin - best_vmin) / step)
+        high = round(Base(step).ge(vmax - best_vmin) / step)
+        return np.arange(low, high + 1) * step + best_vmin + offset
+
+    @cbook.deprecated("2.0")
+    def bin_boundaries(self, vmin, vmax):
+        return self._raw_ticks(vmin, vmax)

    def __call__(self):
        vmin, vmax = self.axis.get_view_interval()
        return self.tick_values(vmin, vmax)

    def tick_values(self, vmin, vmax):
-        vmin, vmax = mtransforms.nonsingular(vmin, vmax, expander=1e-13,
-                                                         tiny=1e-14)
-        locs = self.bin_boundaries(vmin, vmax)
+        vmin, vmax = mtransforms.nonsingular(
+            vmin, vmax, expander=1e-13, tiny=1e-14)
+        locs = self._raw_ticks(vmin, vmax)
        prune = self._prune
        if prune == 'lower':
            locs = locs[1:]
@@ -1482,11 +1487,11 @@ def view_limits(self, dmin, dmax):
                dmin = -maxabs
                dmax = maxabs

-        dmin, dmax = mtransforms.nonsingular(dmin, dmax, expander=1e-12,
-                                                        tiny=1.e-13)
+        dmin, dmax = mtransforms.nonsingular(
+            dmin, dmax, expander=1e-12, tiny=1e-13)

        if rcParams['axes.autolimit_mode'] == 'round_numbers':
-            return np.take(self.bin_boundaries(dmin, dmax), [0, -1])
+            return self._raw_ticks(dmin, dmax)[[0, -1]]
        else:
            return dmin, dmax


diff --git a/lib/mpl_toolkits/tests/baseline_images/test_mplot3d/quiver3d.pdf b/lib/mpl_toolkits/tests/baseline_images/test_mplot3d/quiver3d.pdf
diff --git a/lib/mpl_toolkits/tests/baseline_images/test_mplot3d/quiver3d.png b/lib/mpl_toolkits/tests/baseline_images/test_mplot3d/quiver3d.png