From b1bcc9818eda7292add4dcbcd1fb8e63879b17fc Mon Sep 17 00:00:00 2001
From: Doron Behar <doron.behar@gmail.com>
Date: Wed, 30 Oct 2024 17:29:39 +0200
Subject: [PATCH 1/4] Add anologous tests for LogFormatter_call_big

---
 lib/matplotlib/tests/test_ticker.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lib/matplotlib/tests/test_ticker.py b/lib/matplotlib/tests/test_ticker.py
index 222a0d7e11b0..95c61167aba8 100644
--- a/lib/matplotlib/tests/test_ticker.py
+++ b/lib/matplotlib/tests/test_ticker.py
@@ -1259,6 +1259,13 @@ def test_LogFormatter_call_tiny(self, val):
         temp_lf.axis.set_view_interval(1, 10)
         temp_lf(val)
 
+    @pytest.mark.parametrize('val', [1e+323, 2e+323, 10e+323, 11e+323])
+    def test_LogFormatter_call_big(self, val):
+        # test coeff computation in __call__
+        temp_lf = mticker.LogFormatter()
+        temp_lf.create_dummy_axis()
+        temp_lf(val)
+
 
 class TestLogitFormatter:
     @staticmethod

From b62f5fc27d403dab0f4b9d7de0df4b81f7a94aae Mon Sep 17 00:00:00 2001
From: Doron Behar <doron.behar@gmail.com>
Date: Wed, 17 Jul 2024 17:08:08 +0300
Subject: [PATCH 2/4] test_ticker: add a parameter set for np.inf in
 LogFormatterMathtext

---
 lib/matplotlib/tests/test_ticker.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/matplotlib/tests/test_ticker.py b/lib/matplotlib/tests/test_ticker.py
index 95c61167aba8..e3b5fd846ec2 100644
--- a/lib/matplotlib/tests/test_ticker.py
+++ b/lib/matplotlib/tests/test_ticker.py
@@ -1003,6 +1003,7 @@ class TestLogFormatterMathtext:
         (3, 1e2, '$\\mathdefault{100}$'),
         (3, 1e-3, '$\\mathdefault{10^{-3}}$'),
         (3, 1e3, '$\\mathdefault{10^{3}}$'),
+        (2, np.inf, ''),
     ]
 
     @pytest.mark.parametrize('min_exponent, value, expected', test_data)

From 4a59114378e31bbcc3b0b55560250349397a0473 Mon Sep 17 00:00:00 2001
From: Doron Behar <doron.behar@gmail.com>
Date: Wed, 30 Oct 2024 17:17:54 +0200
Subject: [PATCH 3/4] ticker.py: fix possible np.inf issue with
 LogFormatter{,Mathtext}

---
 lib/matplotlib/ticker.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/matplotlib/ticker.py b/lib/matplotlib/ticker.py
index 0053031ece3e..63a519f7933f 100644
--- a/lib/matplotlib/ticker.py
+++ b/lib/matplotlib/ticker.py
@@ -1001,6 +1001,8 @@ def __call__(self, x, pos=None):
             return '0'
 
         x = abs(x)
+        if not np.isfinite(x):
+            return ''
         b = self._base
         # only label the decades
         fx = math.log(x) / math.log(b)
@@ -1081,6 +1083,8 @@ def __call__(self, x, pos=None):
 
         sign_string = '-' if x < 0 else ''
         x = abs(x)
+        if not np.isfinite(x):
+            return ''
         b = self._base
 
         # only label the decades

From 2357bef77aa92633512652a0877e4bc76ef4e163 Mon Sep 17 00:00:00 2001
From: Doron Behar <doron.behar@gmail.com>
Date: Wed, 29 May 2024 16:21:52 +0300
Subject: [PATCH 4/4] Add test for LogFormatter with very big numbers

Reported at https://github.com/matplotlib/matplotlib/pull/27609 . Values
< 1e300 that trigger this test failure might be found, but it should be
a bit better not to be on the edge of this issue.
---
 lib/matplotlib/tests/test_ticker.py | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/lib/matplotlib/tests/test_ticker.py b/lib/matplotlib/tests/test_ticker.py
index e3b5fd846ec2..376c03478032 100644
--- a/lib/matplotlib/tests/test_ticker.py
+++ b/lib/matplotlib/tests/test_ticker.py
@@ -1843,6 +1843,27 @@ def test_small_range_loglocator(numticks):
         assert (np.diff(np.log10(ll.tick_values(6, 150))) == 1).all()
 
 
+# https://github.com/matplotlib/matplotlib/pull/27609
+# TODO: This test currently fails, as expected and it needs to be fixed...
+# To do this completely correctly, we should figure out what are our limits
+# for when do integers are interpreted eventually as infinities and why,
+# and perhaps always work with np.float128 to increase accuracy as much as
+# possible. Eitherway, we should document what is our limit and how it is
+# related to the accuracy of np.float{64,128} and Python's native float
+# which seems to be the same as np.float64 for this purpose...
+def test_LogFormatter_almost_inf():
+    fig, ax = plt.subplots()
+    # TODO: Figure out why 1e400 won't fail, but will make the ax.plot describe
+    # 1e400 as inf (and hence not print it, and hence not fail).
+    ax.plot([1, 2], [1, 1e300])
+    ax.set_yscale("log")
+    fig.draw_without_rendering()
+    almost_inf = ax.get_lines()[0].get_ydata()[1]
+    # TODO/WIP: remove of course when the above TODOs are fixed. Perhaps assert
+    # something with ydata...
+    assert True == False
+
+
 def test_NullFormatter():
     formatter = mticker.NullFormatter()
     assert formatter(1.0) == ''