--- a
+++ b/tests/limma/test_decidetests.py
@@ -0,0 +1,41 @@
+import unittest
+
+import numpy as np
+
+from inmoose.limma import classifyTestsF
+
+
+class Test(unittest.TestCase):
+    def test_classifyTestsF(self):
+        M = np.arange(1, 13).reshape((3, 4))
+        self.assertTrue(
+            np.array_equal(
+                classifyTestsF(M), [[0, 0, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]
+            )
+        )
+        self.assertTrue(
+            np.array_equal(
+                classifyTestsF(M / 2), [[0, 0, 0, 0], [1, 1, 1, 1], [1, 1, 1, 1]]
+            )
+        )
+        self.assertTrue(
+            np.array_equal(
+                classifyTestsF(M / 3), [[0, 0, 0, 0], [0, 1, 1, 1], [1, 1, 1, 1]]
+            )
+        )
+        self.assertTrue(
+            np.array_equal(
+                classifyTestsF(M, df=3), [[0, 0, 0, 0], [0, 1, 1, 1], [1, 1, 1, 1]]
+            )
+        )
+        self.assertTrue(
+            np.array_equal(
+                classifyTestsF(M, p_value=0.00001),
+                [[0, 0, 0, 1], [1, 1, 1, 1], [1, 1, 1, 1]],
+            )
+        )
+
+        fstat = classifyTestsF(M, fstat_only=True)
+        self.assertTrue(np.array_equal(fstat, [7.5, 43.5, 111.5]))
+        self.assertEqual(fstat.df1, 4)
+        self.assertTrue(np.isposinf(fstat.df2))