diff --git a/lib/matplotlib/tests/test_ticker.py b/lib/matplotlib/tests/test_ticker.py index 611b5cf968d8..9033e30d4858 100644 --- a/lib/matplotlib/tests/test_ticker.py +++ b/lib/matplotlib/tests/test_ticker.py @@ -1347,3 +1347,13 @@ def test_bad_locator_subs(sub): ll = mticker.LogLocator() with pytest.raises(ValueError): ll.subs(sub) + + +@pytest.mark.parametrize('numticks', [1, 2, 3, 9]) +@pytest.mark.style('default') +def test_small_range_loglocator(numticks): + ll = mticker.LogLocator() + ll.set_params(numticks=numticks) + for top in [5, 7, 9, 11, 15, 50, 100, 1000]: + ticks = ll.tick_values(.5, top) + assert (np.diff(np.log10(ll.tick_values(6, 150))) == 1).all() diff --git a/lib/matplotlib/ticker.py b/lib/matplotlib/ticker.py index ced002157637..67931617423f 100644 --- a/lib/matplotlib/ticker.py +++ b/lib/matplotlib/ticker.py @@ -2500,6 +2500,13 @@ def tick_values(self, vmin, vmax): if mpl.rcParams['_internal.classic_mode'] else (numdec + 1) // numticks + 1) + # if we have decided that the stride is as big or bigger than + # the range, clip the stride back to the available range - 1 + # with a floor of 1. This prevents getting axis with only 1 tick + # visible. + if stride >= numdec: + stride = max(1, numdec - 1) + # Does subs include anything other than 1? Essentially a hack to know # whether we're a major or a minor locator. have_subs = len(subs) > 1 or (len(subs) == 1 and subs[0] != 1.0)