import numpy as np

def load_coefficients(filepath):
    """
    Load spectral coefficients from a full-format PROSAIL data file (e.g., dataSpec_PDB.txt).

    Returns:
        wl     : ndarray, wavelength (nm)
        nr     : ndarray, refractive index of leaf material
        Kab    : ndarray, absorption coefficient of chlorophyll (a+b)
        Kcar   : ndarray, absorption coefficient of carotenoids
        Kant   : ndarray, absorption coefficient of anthocyanins
        Kbrown : ndarray, absorption coefficient of brown pigments
        Kw     : ndarray, absorption coefficient of water
        Km     : ndarray, absorption coefficient of dry matter
        Rsoil1 : ndarray, dry soil reflectance
        Rsoil2 : ndarray, wet soil reflectance
    """
    data = np.loadtxt(filepath, comments='%', delimiter=None)

    wl     = data[:, 0]
    nr     = data[:, 1]
    Kab    = data[:, 2]
    Kcar   = data[:, 3]
    Kant   = data[:, 4]
    Kbrown = data[:, 5]
    Kw     = data[:, 6]
    Km     = data[:, 7]
    Rsoil1 = data[:, 10]
    Rsoil2 = data[:, 11]

    return wl, nr, Kab, Kcar, Kant, Kbrown, Kw, Km, Rsoil1, Rsoil2