Add plotting to search filters (#524)

* add search plot to cone search

* unit test

* lint

src/lsdb/core/search/abstract_search.py

@@ -1,10 +1,18 @@
 from __future__ import annotations
 
 from abc import ABC, abstractmethod
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Tuple, Type
 
+import astropy
 import nested_pandas as npd
+from astropy.coordinates import SkyCoord
+from astropy.units import Quantity
+from astropy.visualization.wcsaxes import WCSAxes
+from astropy.visualization.wcsaxes.frame import BaseFrame
 from hats.catalog import TableProperties
+from hats.inspection.visualize_catalog import initialize_wcs_axes
+from matplotlib import pyplot as plt
+from matplotlib.figure import Figure
 from mocpy import MOC
 
 if TYPE_CHECKING:
@@ -32,3 +40,62 @@ def filter_hc_catalog(self, hc_structure: HCCatalogTypeVar) -> MOC:
     @abstractmethod
     def search_points(self, frame: npd.NestedFrame, metadata: TableProperties) -> npd.NestedFrame:
         """Determine the search results within a data frame"""
+
+    def plot(
+        self,
+        projection: str = "MOL",
+        title: str = "",
+        fov: Quantity | Tuple[Quantity, Quantity] | None = None,
+        center: SkyCoord | None = None,
+        wcs: astropy.wcs.WCS | None = None,
+        frame_class: Type[BaseFrame] | None = None,
+        ax: WCSAxes | None = None,
+        fig: Figure | None = None,
+        **kwargs,
+    ):
+        """Plot the search region
+
+        Args:
+            projection (str): The projection to use in the WCS. Available projections listed at
+                https://docs.astropy.org/en/stable/wcs/supported_projections.html
+            title (str): The title of the plot
+            fov (Quantity or Sequence[Quantity, Quantity] | None): The Field of View of the WCS. Must be an
+                astropy Quantity with an angular unit, or a tuple of quantities for different longitude and
+                latitude FOVs (Default covers the full sky)
+            center (SkyCoord | None): The center of the projection in the WCS (Default: SkyCoord(0, 0))
+            wcs (WCS | None): The WCS to specify the projection of the plot. If used, all other WCS parameters
+                are ignored and the parameters from the WCS object is used.
+            frame_class (Type[BaseFrame] | None): The class of the frame for the WCSAxes to be initialized
+                with. if the `ax` kwarg is used, this value is ignored (By Default uses EllipticalFrame for
+                full sky projection. If FOV is set, RectangularFrame is used)
+            ax (WCSAxes | None): The matplotlib axes to plot onto. If None, an axes will be created to be
+                used. If specified, the axes must be an astropy WCSAxes, and the `wcs` parameter must be set
+                with the WCS object used in the axes. (Default: None)
+            fig (Figure | None): The matplotlib figure to add the axes to. If None, one will be created,
+                unless ax is specified (Default: None)
+            **kwargs: Additional kwargs to pass to creating the matplotlib patch object for the search region
+
+        Returns:
+            Tuple[Figure, WCSAxes] - The figure and axes used for the plot
+        """
+        fig, ax, wcs = initialize_wcs_axes(
+            projection=projection,
+            fov=fov,
+            center=center,
+            wcs=wcs,
+            frame_class=frame_class,
+            ax=ax,
+            fig=fig,
+            figsize=(9, 5),
+        )
+        self._perform_plot(ax, **kwargs)
+
+        plt.grid()
+        plt.ylabel("Dec")
+        plt.xlabel("RA")
+        plt.title(title)
+        return fig, ax
+
+    def _perform_plot(self, ax: WCSAxes, **kwargs):
+        """Perform the plot of the search region on an initialized WCSAxes"""
+        raise NotImplementedError("Plotting has not been implemented for this search")

src/lsdb/core/search/cone_search.py

@@ -1,5 +1,7 @@
+import astropy.units as u
 import nested_pandas as npd
 from astropy.coordinates import SkyCoord
+from astropy.visualization.wcsaxes import SphericalCircle, WCSAxes
 from hats.catalog import TableProperties
 from hats.pixel_math.validators import validate_declination_values, validate_radius
 from mocpy import MOC
@@ -31,6 +33,15 @@ def search_points(self, frame: npd.NestedFrame, metadata: TableProperties) -> np
         """Determine the search results within a data frame"""
         return cone_filter(frame, self.ra, self.dec, self.radius_arcsec, metadata)
 
+    def _perform_plot(self, ax: WCSAxes, **kwargs):
+        circle = SphericalCircle(
+            (self.ra * u.deg, self.dec * u.deg),
+            self.radius_arcsec * u.arcsec,
+            transform=ax.get_transform("icrs"),
+            **kwargs,
+        )
+        ax.add_patch(circle)
+
 
 def cone_filter(data_frame: npd.NestedFrame, ra, dec, radius_arcsec, metadata: TableProperties):
     """Filters a dataframe to only include points within the specified cone

tests/lsdb/catalog/test_cone_search.py

@@ -3,8 +3,11 @@
 import pandas as pd
 import pytest
 from astropy.coordinates import SkyCoord
+from astropy.visualization.wcsaxes import SphericalCircle
 from hats.pixel_math.validators import ValidatorsErrors
 
+from lsdb import ConeSearch
+
 
 def test_cone_search_filters_correct_points(small_sky_order1_catalog, assert_divisions_are_correct):
     ra = 0
@@ -124,3 +127,13 @@ def test_empty_cone_search_with_margin(small_sky_order1_source_with_margin):
     cone = small_sky_order1_source_with_margin.cone_search(ra, dec, radius, fine=False)
     assert len(cone._ddf_pixel_map) == 0
     assert len(cone.margin._ddf_pixel_map) == 0
+
+
+def test_cone_search_plot():
+    ra = 100
+    dec = 80
+    radius = 60
+    search = ConeSearch(ra, dec, radius)
+    _, ax = search.plot()
+    assert len(ax.patches) == 1
+    assert isinstance(ax.patches[0], SphericalCircle)