Added 3D scatter test with different z-axis from default

src/napari_matplotlib/scatter.py

@@ -2,6 +2,7 @@
 
 import napari
 import numpy.typing as npt
+from numpy import array
 from qtpy.QtWidgets import QComboBox, QLabel, QVBoxLayout, QWidget
 
 from .base import NapariMPLWidget
@@ -93,6 +94,8 @@ def _get_data(self) -> Tuple[npt.NDArray[Any], npt.NDArray[Any], str, str]:
         """
         x = self.layers[0].data[self.current_z]
         y = self.layers[1].data[self.current_z]
+        print("x data size = ", array(x).shape)
+        print("y data size = ", array(y).shape)
         x_axis_name = self.layers[0].name
         y_axis_name = self.layers[1].name
 

src/napari_matplotlib/tests/scatter/test_scatter.py

@@ -23,3 +23,27 @@ def test_scatter_2D(make_napari_viewer, astronaut_data):
     viewer.layers.selection.add(viewer.layers[0])
     viewer.layers.selection.add(viewer.layers[1])
     return deepcopy(fig)
+
+
+@pytest.mark.mpl_image_compare
+def test_scatter_3D(make_napari_viewer, brain_data):
+    viewer = make_napari_viewer()
+    widget = ScatterWidget(viewer)
+    fig = widget.figure
+
+    viewer.add_image(brain_data[0], **brain_data[1], name="brain")
+
+    viewer.add_image(
+        brain_data[0] * -1, **brain_data[1], name="brain_reversed"
+    )
+    # De-select existing selection
+    viewer.layers.selection.clear()
+    # pdb.set_trace()
+    axis = viewer.dims.last_used
+    slice_no = 9
+    viewer.dims.set_current_step(axis, slice_no)
+    # Select images
+    viewer.layers.selection.add(viewer.layers[0])
+    viewer.layers.selection.add(viewer.layers[1])
+
+    return deepcopy(fig)