Merge pull request #99 from mwcraig/fix-add-single-marker

Add test and fix for case of adding single SkyCoord marker

astrowidgets/core.py

@@ -694,6 +694,11 @@ def add_markers(self, table, x_colname='x', y_colname='y',
             coord_x, coord_y = image.wcs.wcs.all_world2pix(coord_val.ra.deg,
                                                            coord_val.dec.deg,
                                                            0)
+            # In the event a *single* marker has been added, coord_x and coord_y
+            # will be scalars. Make them arrays always.
+            if np.ndim(coord_x) == 0:
+                coord_x = np.array([coord_x])
+                coord_y = np.array([coord_y])
         else:  # Use X,Y
             coord_x = table[x_colname].data
             coord_y = table[y_colname].data

astrowidgets/tests/test_image_widget.py

@@ -299,3 +299,22 @@ def test_empty_marker_name_works_with_all():
     marks = iw.get_markers(marker_name='all')
     assert len(marks) == len(x)
     assert 'empty' not in marks['marker name']
+
+
+def test_add_single_marker():
+    """
+    Test a few things related to naming marker sets
+    """
+    fake_ccd = _make_fake_ccd(with_wcs=True)
+    npix_side = fake_ccd.shape[0]
+    wcs = fake_ccd.wcs
+    iw = ImageWidget(pixel_coords_offset=0)
+    iw.load_nddata(fake_ccd)
+    # Get me 100 positions please, not right at the edge
+    marker_locs = np.random.randint(10,
+                                    high=npix_side - 10,
+                                    size=(100, 2))
+    marks_world = wcs.all_pix2world(marker_locs, 0)
+    marks_coords = SkyCoord(marks_world, unit='degree')
+    mark_coord_table = Table(data=[marks_coords], names=['coord'])
+    iw.add_markers(mark_coord_table[0], use_skycoord=True)