_assign_subclass: signal_shape (1,) now becomes BaseSignal

hyperspy/signal.py

@@ -5367,9 +5367,13 @@ def as_signal2D(self, image_axes, out=None, optimize=True):
 
     def _assign_subclass(self):
         mp = self.metadata
+        if self.axes_manager.signal_shape == (1,):
+            signal_dimension = 0
+        else:
+            signal_dimension = self.axes_manager.signal_dimension
         self.__class__ = hyperspy.io.assign_signal_subclass(
             dtype=self.data.dtype,
-            signal_dimension=self.axes_manager.signal_dimension,
+            signal_dimension=signal_dimension,
             signal_type=mp.Signal.signal_type
             if "Signal.signal_type" in mp
             else self._signal_type,

hyperspy/tests/model/test_model.py

@@ -763,7 +763,7 @@ def test_out_argument(self):
 @lazifyTestClass
 class TestCreateModel:
     def setup_method(self, method):
-        self.s = hs.signals.Signal1D(np.asarray([0]))
+        self.s = hs.signals.Signal1D(np.asarray([0, 1]))
         self.im = hs.signals.Signal2D(np.ones([1, 1]))
 
     def test_create_model(self):

hyperspy/tests/signals/test_assign_subclass.py

@@ -87,6 +87,21 @@ def test_id_set_signal_type():
     assert id_om == id(s.original_metadata)
 
 
+class TestToBaseSignal:
+
+    def setup_method(self, method):
+        self.s = hs.signals.Signal1D(np.array([0]))
+
+    def test_simple(self):
+        self.s._assign_subclass()
+        assert isinstance(self.s, hs.signals.BaseSignal)
+
+    def test_lazy(self):
+        self.s._lazy = True
+        self.s._assign_subclass()
+        assert isinstance(self.s, _lazy_signals.LazySignal)
+
+
 class TestConvertBaseSignal:
 
     def setup_method(self, method):
@@ -122,7 +137,7 @@ def test_base_to_complex(self):
 class TestConvertSignal1D:
 
     def setup_method(self, method):
-        self.s = hs.signals.Signal1D([0])
+        self.s = hs.signals.Signal1D([0, 1])
 
     def test_lazy_to_eels_and_back(self):
         self.s = self.s.as_lazy()
@@ -176,7 +191,7 @@ def test_complex_to_complex2d(self):
 class TestConvertComplexSignal1D:
 
     def setup_method(self, method):
-        self.s = hs.signals.ComplexSignal1D([0])
+        self.s = hs.signals.ComplexSignal1D([0, 1])
 
     def test_complex_to_dielectric_function(self):
         self.s.set_signal_type("DielectricFunction")

upcoming_changes/2773.bugfix.rst

@@ -0,0 +1 @@
+Signals with 1 value in the signal dimension will now be :py:class:`~.signal.BaseSignal`