hats.inspection.visualize_catalog

hats.inspection.visualize_catalog#

Generate a molleview map with the pixel densities of the catalog

NB: Testing validity of generated plots is currently not tested in our unit test suite.

Functions#

`plot_density`(catalog, *[, plot_title, order, unit])	Create a visual map of the density of input points of a catalog on-disk.
`plot_pixels`(catalog[, plot_title])	Create a visual map of the pixel density of the catalog.
`plot_pixel_list`(pixels[, plot_title, projection, ...])	Create a visual map of the pixel density of a list of pixels.
`plot_moc`(→ tuple[matplotlib.figure.Figure, ...)	Plots a moc
`plot_healpix_map`(healpix_map, *[, projection, title, ...])	Plot a map of HEALPix pixels to values as a colormap across a projection of the sky

Module Contents#

plot_density(catalog: hats.catalog.Catalog, *, plot_title: str | None = None, order=None, unit=None, **kwargs)[source]#

Create a visual map of the density of input points of a catalog on-disk.

Parameters:

catalog: Catalog: on-disk catalog object
plot_titlestr | None: Optional title for the plot
orderint: Optionally reduce the display healpix order, and aggregate smaller tiles. (Default value = None)
unitastropy.units.Unit: Unit to show for the angle for angular density. (Default value = None)
**kwargs: Additional args to pass to plot_healpix_map

plot_pixels(catalog: hats.catalog.healpix_dataset.healpix_dataset.HealpixDataset, plot_title: str | None = None, **kwargs)[source]#

Create a visual map of the pixel density of the catalog.

Parameters:

plot_titlestr | None: Optional title for the plot
catalog: HealpixDataset: on-disk or in-memory catalog, with healpix pixels.
**kwargs: Additional args to pass to plot_healpix_map

plot_pixel_list(pixels: list[hats.pixel_math.HealpixPixel], plot_title: str = '', projection='MOL', color_by_order=True, **kwargs)[source]#

Create a visual map of the pixel density of a list of pixels.

Parameters:

pixelslist[HealpixPixel]: healpix pixels (order and pixel number) to visualize
plot_titlestr: (Default value = “”) heading for the plot
projectionstr: The projection to use. Available projections listed at https://docs.astropy.org/en/stable/wcs/supported_projections.html (Default value = “MOL”)
color_by_orderbool: Whether to color the pixels by their order. True by default.
**kwargs: Additional args to pass to plot_healpix_map

plot_moc(moc: mocpy.MOC, *, projection: str = 'MOL', title: str = '', fov: astropy.units.Quantity | tuple[astropy.units.Quantity, astropy.units.Quantity] = None, center: astropy.coordinates.SkyCoord | None = None, wcs: astropy.wcs.WCS = None, frame_class: Type[astropy.visualization.wcsaxes.frame.BaseFrame] | None = None, ax: astropy.visualization.wcsaxes.WCSAxes | None = None, fig: matplotlib.figure.Figure | None = None, **kwargs) → tuple[matplotlib.figure.Figure, astropy.visualization.wcsaxes.WCSAxes][source]#

Plots a moc

By default, a new matplotlib figure and axis will be created, and the projection will be a Molleweide projection across the whole sky.

Parameters:

mocmocpy.MOC: MOC to plot
projectionstr: The projection to use in the WCS. Available projections listed at https://docs.astropy.org/en/stable/wcs/supported_projections.html (Default value = “MOL”)
titlestr: The title of the plot (Default value = “”)
fovQuantity | tuple[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)
centerSkyCoord | None: The center of the projection in the WCS (Default: SkyCoord(0, 0))
wcsWCS | 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_classType[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)
axWCSAxes | 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)
figFigure | 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 mocpy.MOC.fill

Returns:

Tuple[Figure, WCSAxes]: The figure and axes used to plot the healpix map

plot_healpix_map(healpix_map: numpy.ndarray, *, projection: str = 'MOL', title: str = '', cmap: str | matplotlib.colors.Colormap = 'viridis', norm: matplotlib.colors.Normalize | None = None, ipix: numpy.ndarray | None = None, depth: numpy.ndarray | None = None, cbar: bool = True, fov: astropy.units.Quantity | tuple[astropy.units.Quantity, astropy.units.Quantity] = None, center: astropy.coordinates.SkyCoord | None = None, wcs: astropy.wcs.WCS = None, frame_class: Type[astropy.visualization.wcsaxes.frame.BaseFrame] | None = None, ax: astropy.visualization.wcsaxes.WCSAxes | None = None, fig: matplotlib.figure.Figure | None = None, **kwargs)[source]#

Plot a map of HEALPix pixels to values as a colormap across a projection of the sky

Plots the given healpix pixels on a spherical projection defined by a WCS. Colors each pixel based on the corresponding value in a map. The map can be across all healpix pixels at a given order, or specify a subset of healpix pixels with the ipix and depth parameters.

By default, a new matplotlib figure and axis will be created, and the projection will be a Molleweide projection across the whole sky. Additional kwargs will be passed to the creation of a matplotlib PathCollection object, which is the artist that draws the tiles.

Parameters:

healpix_mapnp.ndarray: Array of map values for the healpix tiles. If ipix and depth are not specified, the length of this array will be used to determine the healpix order, and will plot healpix pixels with pixel index corresponding to the array index in NESTED ordering. If ipix and depth are specified, all arrays must be of the same length, and the pixels specified by the ipix and depth arrays will be plotted with their values specified in the healpix_map array.
projectionstr: The projection to use in the WCS. Available projections listed at https://docs.astropy.org/en/stable/wcs/supported_projections.html
titlestr: The title of the plot
cmapstr | Colormap: The matplotlib colormap to plot with
normNormalize | None: The matplotlib normalization to plot with
ipixnp.ndarray | None: Array of HEALPix NESTED pixel indices. Must be used with depth, and arrays must be the same length
depthnp.ndarray | None: Array of HEALPix pixel orders. Must be used with ipix, and arrays must be the same length
cbarbool: If True, includes a color bar in the plot (Default: True)
fovQuantity or Quantity | tuple[Quantity, Quantity]: 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)
centerSkyCoord | None: The center of the projection in the WCS (Default: SkyCoord(0, 0))
wcsWCS | 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_classType[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)
axWCSAxes | 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)
figFigure | 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 PathCollection artist

Returns:

Tuple[Figure, WCSAxes]: The figure and axes used to plot the healpix map