fix the automatic limits for when n_obs is near a power of 10

.gitignore

@@ -74,3 +74,7 @@ target/
 # image comparison
 baseline
 figcomp
+
+# exploratory things
+*scratch*
+__marimo__

probscale/probscale.py

@@ -227,6 +227,7 @@ def set_default_locators_and_formatters(self, axis: Axis) -> None:
             axis.set_major_formatter(FuncFormatter(PctFormatter()))
         else:
             axis.set_major_formatter(FuncFormatter(ProbFormatter()))
+
         axis.set_minor_locator(NullLocator())
         axis.set_minor_formatter(NullFormatter())
 

probscale/tests/test_viz.py

@@ -1051,7 +1051,14 @@ def test_probplot_test_results(plot_data):
 @pytest.mark.parametrize("probax", ["x", "y"])
 @pytest.mark.parametrize(
     ("N", "minval", "maxval"),
-    [(5, 10, 90), (8, 5, 95), (37, 1, 99), (101, 0.1, 99.9), (10001, 0.001, 99.999)],
+    [
+        (5, 10, 90),
+        (8, 5, 95),
+        (37, 1, 99),
+        (100, 0.1, 99.9),
+        (101, 0.1, 99.9),
+        (10001, 0.001, 99.999),
+    ],
 )
 def test__set_prob_limits_x(probax, N, minval, maxval):
     from probscale import validate

probscale/viz.py

@@ -488,10 +488,11 @@ def _set_prob_limits(ax: Axes, probax: str, N: int) -> None:
     elif N <= 10:
         minval = 5
     else:
-        minval = 10 ** (-1 * numpy.ceil(numpy.log10(N) - 2))
+        minval = 10 ** (1 - numpy.floor(numpy.log10(N)))
 
     if which in ["x", "both"]:
         ax.set_xlim(left=minval, right=100 - minval)
+
     elif which in ["y", "both"]:
         ax.set_ylim(bottom=minval, top=100 - minval)