Add unit test for sino normalization with array subtraction

nabu/reconstruction/tests/test_sino_normalization.py

@@ -28,7 +28,7 @@ class TestSinoNormalization:
 
 
     @pytest.mark.skipif(not(__has_pycuda__), reason="Need pycuda for sinogram normalization with cuda backend")
-    def test_dff_cuda(self):
+    def test_sino_normalization_cuda(self):
         sino_proc = SinoNormalization(
             kind="chebyshev", sinos_shape=self.sino.shape
         )
@@ -44,3 +44,23 @@ class TestSinoNormalization:
 
         assert np.max(np.abs(res - ref)) < self.tol
 
+
+    def test_sino_array_subtraction(self):
+        with pytest.raises(ValueError):
+            SinoNormalization(kind="subtract_array", sinos_shape=self.sino.shape)
+
+        array_1D = np.arange(self.sino.shape[-1])
+        array_2D = np.arange(self.sino.size).reshape(self.sino.shape)
+
+        def compare_normalizations(normalization_arr):
+            sino_normalization = SinoNormalization(
+                kind="subtract_array", sinos_shape=self.sino.shape,
+                normalization_array=normalization_arr
+            )
+            sino = self.sino.copy()
+            sino_normalization.normalize(sino)
+            ref = self.sino - normalization_arr
+            assert np.allclose(sino, ref)
+
+        compare_normalizations(array_1D)
+        compare_normalizations(array_2D)