_assign_subclass: signal_shape (1,) now becomes BaseSignal

hyperspy/axes.py

@@ -1203,19 +1203,18 @@ def _update_attributes(self):
         self.signal_axes = self.signal_axes[::-1]
         self.navigation_axes = self.navigation_axes[::-1]
         self._getitem_tuple = tuple(getitem_tuple)
-        self.signal_dimension = len(self.signal_axes)
+        if len(self.signal_axes) == 1 and self.signal_axes[0].size == 1:
+            self.signal_dimension = 0
+        else:
+            self.signal_dimension = len(self.signal_axes)
         self.navigation_dimension = len(self.navigation_axes)
         if self.navigation_dimension != 0:
             self.navigation_shape = tuple([
                 axis.size for axis in self.navigation_axes])
         else:
             self.navigation_shape = ()
 
-        if self.signal_dimension != 0:
-            self.signal_shape = tuple([
-                axis.size for axis in self.signal_axes])
-        else:
-            self.signal_shape = ()
+        self.signal_shape = tuple([axis.size for axis in self.signal_axes])
         self.navigation_size = (np.cumprod(self.navigation_shape)[-1]
                                 if self.navigation_shape else 0)
         self.signal_size = (np.cumprod(self.signal_shape)[-1]

hyperspy/misc/signal_tools.py

@@ -171,7 +171,7 @@ def broadcast_signals(*args, ignore_axis=None):
         for s in args:
             data = s._data_aligned_with_axes
             sam = s.axes_manager
-            sdim_diff = len(new_sig_axes) - sam.signal_dimension
+            sdim_diff = len(new_sig_axes) - len(sam.signal_axes)
             while sdim_diff > 0:
                 slices = (slice(None),) * sam.navigation_dimension
                 slices += (None, Ellipsis)

hyperspy/signal.py

@@ -2619,6 +2619,11 @@ def plot(self, navigator="auto", axes_manager=None, plot_markers=True,
             else:
                 navigator = "slider"
         if axes_manager.signal_dimension == 0:
+            if axes_manager.navigation_dimension == 0:
+                # 0d signal without navigation axis: don't make a figure
+                # and instead, we display the value
+                print(self.data)
+                return
             self._plot = mpl_he.MPL_HyperExplorer()
         elif axes_manager.signal_dimension == 1:
             # Hyperspectrum

hyperspy/tests/drawing/test_plot_signal.py

@@ -314,3 +314,9 @@ def test_plot_autoscale(sdim):
 
     s.change_dtype(bool)
     s.plot()
+
+
+def test_plot_signal_scalar():
+    s = hs.signals.BaseSignal([1.0])
+    s.plot()
+    assert s._plot is None

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_2D.py

@@ -23,14 +23,16 @@
 import pytest
 
 from hyperspy.decorators import lazifyTestClass
+from hyperspy.signal import BaseSignal
 from hyperspy.signals import Signal1D, Signal2D
 
 
 def _verify_test_sum_x_E(self, s):
     np.testing.assert_array_equal(self.signal.data.sum(), s.data)
     assert s.data.ndim == 1
-    # Check that there is still one signal axis.
-    assert s.axes_manager.signal_dimension == 1
+    # Check that the signal dimension is now 0
+    assert s.axes_manager.signal_dimension == 0
+    assert isinstance(s, BaseSignal)
 
 
 @lazifyTestClass

hyperspy/tests/signals/test_3D.py

@@ -183,7 +183,7 @@ def test_get_navigation_signal_nav_dim0(self):
         s = self.signal
         s = s.transpose(signal_axes=3)
         ns = s._get_navigation_signal()
-        assert ns.axes_manager.signal_dimension == 1
+        assert ns.axes_manager.signal_dimension == 0
         assert ns.axes_manager.signal_size == 1
         assert ns.axes_manager.navigation_dimension == 0
 
@@ -233,7 +233,7 @@ def test_get_signal_signal_nav_dim0(self):
         ns = s._get_signal_signal()
         assert ns.axes_manager.navigation_dimension == 0
         assert ns.axes_manager.navigation_size == 0
-        assert ns.axes_manager.signal_dimension == 1
+        assert ns.axes_manager.signal_dimension == 0
 
     def test_get_signal_signal_nav_dim1(self):
         s = self.signal

hyperspy/tests/signals/test_assign_subclass.py

@@ -24,6 +24,7 @@
 
 import hyperspy.api as hs
 from hyperspy import _lazy_signals
+from hyperspy.decorators import lazifyTestClass
 from hyperspy.exceptions import VisibleDeprecationWarning
 from hyperspy.io import assign_signal_subclass
 
@@ -87,6 +88,21 @@ def test_id_set_signal_type():
     assert id_om == id(s.original_metadata)
 
 
+@lazifyTestClass
+class TestToBaseSignalScalar:
+
+    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)
+        assert self.s.axes_manager.signal_dimension == 0
+        assert self.s.axes_manager.signal_shape == (1, )
+        if self.s._lazy:
+            assert isinstance(self.s, _lazy_signals.LazySignal)
+
+
 class TestConvertBaseSignal:
 
     def setup_method(self, method):
@@ -122,7 +138,7 @@ 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 +192,7 @@ 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`