Add plot_pixels method to Catalog (#229)

src/lsdb/catalog/dataset/healpix_dataset.py

@@ -9,6 +9,7 @@
 import pandas as pd
 from dask.delayed import Delayed, delayed
 from hipscat.catalog.healpix_dataset.healpix_dataset import HealpixDataset as HCHealpixDataset
+from hipscat.inspection import plot_pixel_list
 from hipscat.pixel_math import HealpixPixel
 from hipscat.pixel_math.healpix_pixel_function import get_pixel_argsort
 from typing_extensions import Self
@@ -232,6 +233,19 @@ def skymap(self, func: Callable[[pd.DataFrame, HealpixPixel], Any], **kwargs):
         result_dict = {pixels[i]: results[i] for i in range(len(pixels))}
         plot_skymap(result_dict)
 
+    def plot_pixels(self, projection: str = "moll", **kwargs):
+        """Create a visual map of the pixel density of the catalog.
+
+        Args:
+            projection (str) The map projection to use. Valid values include:
+                - moll - Molleweide projection (default)
+                - gnom - Gnomonic projection
+                - cart - Cartesian projection
+                - orth - Orthographic projection
+            kwargs (dict): additional keyword arguments to pass to plotting call.
+        """
+        plot_pixel_list(self.get_healpix_pixels(), projection, **kwargs)
+
     def to_hipscat(
         self,
         base_catalog_path: str,

tests/lsdb/catalog/test_catalog.py

@@ -309,3 +309,17 @@ def func(df, healpix):
         img[img_order_pixels] = value
     hp.mollview.assert_called_once()
     assert (hp.mollview.call_args[0][0] == img).all()
+
+
+# pylint: disable=no-member
+def test_plot_pixels(small_sky_order1_catalog, mocker):
+    mocker.patch("healpy.mollview")
+
+    small_sky_order1_catalog.plot_pixels()
+
+    # Everything will be empty, except the four pixels at order 1.
+    img = np.full(48, hp.pixelfunc.UNSEEN)
+    img[[44, 45, 46, 47]] = 1
+
+    hp.mollview.assert_called_once()
+    assert (hp.mollview.call_args[0][0] == img).all()