Backport PR #19371: Fix specgram test on NumPy 1.20.

dstansby · meeseeksmachine · commit 638165699d98 · 2021-01-27T14:38:05.000Z
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -4152,7 +4152,7 @@ def test_specgram_angle():
 
 def test_specgram_fs_none():
     """Test axes.specgram when Fs is None, should not throw error."""
-    spec, freqs, t, im = plt.specgram(np.ones(300), Fs=None)
+    spec, freqs, t, im = plt.specgram(np.ones(300), Fs=None, scale='linear')
     xmin, xmax, freq0, freq1 = im.get_extent()
     assert xmin == 32 and xmax == 96
 
