Fix triggering event range widget

hyperspy/drawing/_widgets/range.py

@@ -144,6 +144,7 @@ def _span_changed(self, *args, **kwargs):
         extents = self.span.extents
         self._pos = np.array([extents[0]])
         self._size = np.array([extents[1] - extents[0]])
+        self.events.changed.trigger(self)
 
     def _get_range(self):
         p = self._pos[0]

hyperspy/drawing/signal1d.py

@@ -177,13 +177,20 @@ def plot(self, data_function_kwargs={}, **kwargs):
         self.ax.set_title(self.title)
         x_axis_upper_lims = []
         x_axis_lower_lims = []
+
         for line in self.ax_lines:
             line.plot(data_function_kwargs=data_function_kwargs, **kwargs)
-            x_axis_lower_lims.append(line.axis.axis[0])
-            x_axis_upper_lims.append(line.axis.axis[-1])
+            if len(line.axis.axis) > 1:
+                x_axis_lower_lims.append(line.axis.axis[0])
+                x_axis_upper_lims.append(line.axis.axis[-1])
+
         for marker in self.ax_markers:
             marker.plot(render_figure=False)
-        plt.xlim(np.min(x_axis_lower_lims), np.max(x_axis_upper_lims))
+
+        plt.xlim(min(x_axis_lower_lims, default=None),
+                 max(x_axis_upper_lims, default=None)
+                 )
+
         self.axes_manager.events.indices_changed.connect(self.update, [])
         self.events.closed.connect(
             lambda: self.axes_manager.events.indices_changed.disconnect(
@@ -484,28 +491,36 @@ def update(self, force_replot=False, render_figure=True,
         else:
             self.line.set_ydata(ydata)
 
-        if 'x' in self.autoscale:
-            self.ax.set_xlim(axis[0], axis[-1])
+        # Don't change xlim if axis has 0 length (unnecessary)
+        if 'x' in self.autoscale and len(axis) > 0:
+            x_min, x_max = axis[0], axis[-1]
+            if x_min == x_max:
+                # To avoid matplotlib UserWarning when calling `set_ylim`
+                x_min, x_max = (x_min - 0.1, x_min + 0.1)
+            self.ax.set_xlim(x_min, x_max)
 
-        if 'v' in self.autoscale:
+        # Don't change ymin if data has 0 length (unnecessary)
+        if 'v' in self.autoscale and len(ydata) > 0:
             self.ax.relim()
-            y1, y2 = np.searchsorted(axis, self.ax.get_xbound())
-            y2 += 2
-            y1, y2 = np.clip((y1, y2), 0, len(ydata - 1))
-            clipped_ydata = ydata[y1:y2]
+            # Based on the current zoom of the x axis, find the corresponding
+            # y range of data and calculate the y_min, y_max accordingly
+            i1, i2 = np.searchsorted(axis, self.ax.get_xbound())
+            # Make interval wider on both side and clip to allowed range
+            i1, i2 = np.clip((i1-1, i2+1), 0, len(ydata - 1))
+            ydata = ydata[i1:i2]
+
             with ignore_warning(category=RuntimeWarning):
                 # In case of "All-NaN slices"
-                y_max, y_min = (np.nanmax(clipped_ydata),
-                                np.nanmin(clipped_ydata))
+                y_max, y_min = np.nanmax(ydata), np.nanmin(ydata)
 
             if self._plot_imag:
                 # Add real plot
-                yreal = self._get_data(real_part=True)
-                clipped_yreal = yreal[y1:y2]
+                yreal = self._get_data(real_part=True)[i1:i2]
                 with ignore_warning(category=RuntimeWarning):
                     # In case of "All-NaN slices"
-                    y_min = min(y_min, np.nanmin(clipped_yreal))
-                    y_max = max(y_max, np.nanmin(clipped_yreal))
+                    y_min = min(y_min, np.nanmin(yreal))
+                    y_max = max(y_max, np.nanmin(yreal))
+
             if y_min == y_max:
                 # To avoid matplotlib UserWarning when calling `set_ylim`
                 y_min, y_max = y_min - 0.1, y_max + 0.1

hyperspy/interactive.py

@@ -127,8 +127,18 @@ def update(self):
 
 
 def interactive(f, event="auto", recompute_out_event="auto", *args, **kwargs):
+    """
+    %s
+
+    Returns
+    -------
+    :py:class:`~hyperspy.signal.BaseSignal` or one of its subclass
+        Signal updated with the operation result when a given event is
+        triggered.
+
+    """
     cls = Interactive(f, event, recompute_out_event, *args, **kwargs)
     return cls.out
 
 
-interactive.__doc__ = Interactive.__init__.__doc__
+interactive.__doc__ %= Interactive.__init__.__doc__

hyperspy/roi.py

@@ -334,8 +334,8 @@ def _update_widgets(self, exclude=None):
         """Internal function for updating the associated widgets to the
         geometry contained in the ROI.
 
-        Arguments
-        ---------
+        Parameters
+        ----------
         exclude : set()
             A set of widgets to exclude from the update. Useful e.g. if a
             widget has triggered a change in the ROI: Then all widgets,
@@ -379,10 +379,10 @@ def _set_from_widget(self, widget):
     def interactive(self, signal, navigation_signal="same", out=None,
                     color="green", snap=True, **kwargs):
         """Creates an interactively sliced Signal (sliced by this ROI) via
-        hyperspy.interactive.
+        :py:func:`~.interactive.interactive`.
 
-        Arguments
-        ---------
+        Parameters
+        ----------
         signal : Signal
             The source signal to slice.
         navigation_signal : Signal, None or "same" (default)
@@ -406,6 +406,12 @@ def interactive(self, signal, navigation_signal="same", out=None,
             All kwargs are passed to the roi __call__ method which is called
             interactively on any roi parameter change.
 
+        Returns
+        -------
+        :py:class:`~hyperspy.signal.BaseSignal` or one of its subclass
+            Signal updated with the current ROI selection 
+            when the ROI is changed.
+
         """
         if hasattr(signal, '_plot_kwargs'):
             kwargs.update({'_plot_kwargs': signal._plot_kwargs})
@@ -460,8 +466,8 @@ def add_widget(self, signal, axes=None, widget=None, color='green',
         changes in either are reflected in the other. Note that only one
         widget can be added per signal/axes combination.
 
-        Arguments
-        ---------
+        Parameters
+        ----------
         signal : Signal
             The signal to which the widget is added. This is used to determine
             which plot to add the widget to, and it supplies the axes_manager
@@ -479,6 +485,10 @@ def add_widget(self, signal, axes=None, widget=None, color='green',
             True.
         kwargs:
             All keyword arguments are passed to the widget constructor.
+
+        Returns
+        -------
+        The widget of the ROI.
         """
 
         axes = self._parse_axes(axes, signal.axes_manager,)

hyperspy/tests/drawing/test_plot_roi_widgets.py

@@ -231,3 +231,18 @@ def test_snapping_axis_values(snap):
     r = roi.Line2DROI(x1=6, y1=0, x2=12, y2=4, linewidth=0)
     s.plot()
     _ = r.interactive(s, snap=snap)
+
+
+def test_plot_span_roi_changed_event():
+    s = Signal1D(np.arange(100))
+    s.plot()
+    r = roi.SpanROI()
+    s_span = r.interactive(s)
+    np.testing.assert_allclose(s_span.data, np.arange(25, 74))
+
+    w = list(r.widgets)[0]
+    assert w._pos == (24.5, )
+    assert w._size == (50., )
+    w._set_span_extents(10, 20)
+    np.testing.assert_allclose(s_span.data, np.arange(9, 19))
+

hyperspy/tests/drawing/test_plot_signal.py

@@ -321,6 +321,9 @@ def test_plot_complex_representation():
     imag_ref = np.arange(9).reshape((3, 3)) + 9
     comp_ref = real_ref + 1j * imag_ref
     s = hs.signals.ComplexSignal1D(comp_ref)
+    s.plot()
+    # change indices to trigger update
+    s.axes_manager.indices = (1, )    
     s.plot(representation='polar', same_axes=True)
     s.plot(representation='polar', same_axes=False)
     with pytest.raises(ValueError):

hyperspy/tests/drawing/test_plot_signal1d.py

@@ -402,3 +402,19 @@ def test_plot_spectra_linestyle_error():
 
     with pytest.raises(ValueError):
         hs.plot.plot_spectra(s, linestyle='invalid')
+
+
+def test_plot_empty_slice_autoscale():
+    s = hs.signals.Signal1D(np.arange(100))
+    s.plot()
+    r = hs.roi.SpanROI()
+    s_span = r.interactive(s)
+    s_span.plot(autoscale='x')
+    # change span selector to an "empty" slice and trigger update
+    r.left = 24
+    r.right = 24.1
+
+    s_span.plot(autoscale='v')
+    # change span selector to an "empty" slice and trigger update
+    r.left = 23
+    r.right = 23.1

upcoming_changes/2952.bugfix.rst

@@ -0,0 +1 @@
+Fix :py:class:`~.roi.SpanROI` regression: the output of :py:meth:`~.roi.BaseInteractiveROI.interactive` was not updated when the ROI was changed. Fix errors with updating limits when plotting empty slice of data. Improve docstrings and test coverage.