adds missing Shen+2020 module

#!/usr/bin/env python3

# Author: Akke Viitanen

# Email: akke.viitanen@helsinki.fi

# Date: 2025-09-23 16:04:03

"""

Wrapper for Shen+2020 data

"""

from functools import cache

import astropy.units as u

import numpy as np

from quasarlf.pubtools.load_observations import get_data

def get_phi_shen2020(z):

    """

    Return Shen+2020 luminosity function dataset for the given redshift.

    Parameters

    ----------

    z: float

        redshift of interest

    Returns

    -------

    4-element list of luminosity function datasets corresponding to the

    wavelength 15um, 4400angstrom, 1450angstrom and 2-10 keV, respectively.

    Refer to Shen+2020 quasarlf library for the details.

    """

    @cache

    def get(dataid: int, lam: u.Quantity, z: float):

        """

        Return a single dataset corresponding to dataid, wavelength and redshift.

        """

        # Return the Shen luminosity function for a single dataid

        x, y, dy, dx = get_data(dataid, z)

        if dataid == -4:

            L_solar_in_cgs = np.log10(u.L_sun.cgs.scale)

            x += L_solar_in_cgs

        if dataid in (-2, -1):

            # Convert from Lsun / dex to ABmag / mag

            x = 10**x * u.L_sun / lam.to(u.Hz, equivalencies=u.spectral())

            L_AB = 3631.0 * u.Jy * 4 * np.pi * (10 * u.pc) ** 2

            x = -2.5 * np.log10((x / L_AB).cgs)

            y -= np.log10(2.5)

        return x, dx, y, dy

    dataset = [(-2, 15.0 * u.um), (-1, 4400 * u.angstrom), (-5, 1450 * u.angstrom), (-4, None)]

    return [get(dataid, lam, z) for dataid, lam in dataset]