"""
Module for BT-Settl atmospheric model spectra.
"""
import os
import tarfile
import warnings
import urllib.request
try:
import lzma
except ModuleNotFoundError:
warnings.warn('Could not import the lzma module. Attempting to use lzma compression will '
'result in a RuntimeError.')
import spectres
import numpy as np
from species.util import data_util
[docs]def add_btsettl(input_path,
database,
wavel_range,
teff_range,
spec_res):
"""
Function for adding the BT-Settl atmospheric models (solar metallicity) to the database.
The spectra are read line-by-line because the wavelength and flux are not separated in the
input data.
Parameters
----------
input_path : str
Folder where the data is located.
database : h5py._hl.files.File
Database.
wavel_range : tuple(float, float)
Wavelength range (um).
teff_range : tuple(float, float), None
Effective temperature range (K).
spec_res : float
Spectral resolution.
Returns
-------
NoneType
None
"""
if not os.path.exists(input_path):
os.makedirs(input_path)
data_folder = os.path.join(input_path, 'bt-settl/')
input_file = 'SPECTRA.tar'
url = 'https://phoenix.ens-lyon.fr/Grids/BT-Settl/CIFIST2011c/SPECTRA.tar'
data_file = os.path.join(input_path, input_file)
if not os.path.isfile(data_file):
print('Downloading BT-Settl model spectra (8.1 GB)...', end='', flush=True)
urllib.request.urlretrieve(url, data_file)
print(' [DONE]')
print('Unpacking BT-Settl model spectra (8.1 GB)...', end='', flush=True)
tar = tarfile.open(data_file)
tar.extractall(data_folder)
tar.close()
print(' [DONE]')
data_folder = os.path.join(data_folder, 'SPECTRA')
teff = []
logg = []
flux = []
wavelength = [wavel_range[0]]
while wavelength[-1] <= wavel_range[1]:
wavelength.append(wavelength[-1] + wavelength[-1]/(2.*spec_res))
wavelength = np.asarray(wavelength[:-1])
for _, _, file_list in os.walk(data_folder):
for filename in sorted(file_list):
if filename.startswith('lte') and filename.endswith('.7.xz'):
if len(filename) == 38:
teff_val = float(filename[3:6])*100.
logg_val = float(filename[7:10])
feh_val = float(filename[11:14])
elif len(filename) == 40:
teff_val = float(filename[3:8])*100.
logg_val = float(filename[9:12])
feh_val = float(filename[13:16])
else:
raise ValueError('The length of the filename is not compatible for reading '
'the parameter values.')
if teff_range is not None:
if teff_val < teff_range[0] or teff_val > teff_range[1]:
continue
if feh_val != 0.:
continue
print_message = f'Adding BT-Settl model spectra... {filename}'
print(f'\r{print_message:<80}', end='')
data_wavel = []
data_flux = []
with lzma.open(os.path.join(data_folder, filename), mode='rt') as xz_file:
for line in xz_file:
line = line[:line.find('D')+4].split()
if len(line) == 1:
line = line[0]
wavel_tmp = line[:line.find('-')]
flux_tmp = line[line.find('-'):]
elif len(line) == 2:
wavel_tmp = line[0]
flux_tmp = line[1]
# (Angstrom) -> (um)
data_wavel.append(float(wavel_tmp)*1e-4)
# See https://phoenix.ens-lyon.fr/Grids/FORMAT
flux_cgs = 10.**(float(flux_tmp.replace('D', 'E'))-8.)
# (erg s-1 cm-2 Angstrom-1) -> (W m-2 um-1)
data_flux.append(flux_cgs*1e-7*1e4*1e4)
data = np.stack((data_wavel, data_flux), axis=1)
index_sort = np.argsort(data[:, 0])
data = data[index_sort, :]
if np.all(np.diff(data[:, 0]) < 0):
raise ValueError('The wavelengths are not all sorted by increasing value.')
teff.append(teff_val)
logg.append(logg_val)
try:
flux.append(spectres.spectres(wavelength, data[:, 0], data[:, 1]))
except ValueError:
flux.append(np.zeros(wavelength.shape[0]))
warnings.warn('The wavelength range should fall within the range of the '
'original wavelength sampling. Storing zeros instead.')
data_sorted = data_util.sort_data(np.asarray(teff),
np.asarray(logg),
None,
None,
None,
wavelength,
np.asarray(flux))
data_util.write_data('bt-settl', ['teff', 'logg'], database, data_sorted)
print_message = 'Adding BT-Settl model spectra... [DONE]'
print(f'\r{print_message:<80}')