import os
import tarfile
import numpy as np
from astropy.table import Table
from . import get_data_home
from .tools import download_with_progress_bar
TARGETLIST_URL = ("https://github.com/astroML/astroML-data/raw/master/datasets/"
"allLINEARfinal_targets.dat.gz")
DATA_URL = ("https://github.com/astroML/astroML-data/raw/master/datasets/"
"allLINEARfinal_dat.tar.gz")
GENEVA_URL = ("https://github.com/astroML/astroML-data/raw/master/datasets/"
"LINEARattributesFinalApr2013.dat.gz")
GENEVA_ARCHIVE = 'LINEARattributesFinalApr2013.npy'
ARCHIVE_DTYPE = ([(s, 'f8') for s in ('RA', 'Dec', 'ug', 'gi', 'iK',
'JK', 'logP', 'Ampl', 'skew',
'kurt', 'magMed', 'nObs')]
+ [('LCtype', 'i4'), ('LINEARobjectID', '|S20')])
target_names = ['objectID', 'raLIN', 'decLIN', 'raSDSS', 'decSDSS', 'r',
'ug', 'gr', 'ri', 'iz', 'JK', '<mL>', 'std', 'rms',
'Lchi2', 'LP1', 'phi1', 'S', 'prior']
class LINEARdata:
"""A container class for the linear dataset.
Because the dataset is often not needed all at once, this class
offers tools to access just the needed components
Example
-------
>>> data = fetch_LINEAR_sample() # doctest: +IGNORE_OUTPUT +REMOTE_DATA
>>> lightcurve = data[data.ids[0]] # doctest: +REMOTE_DATA
"""
@staticmethod
def _name_to_id(name):
return int(name.split('.')[0])
@staticmethod
def _id_to_name(id):
return str(id) + '.dat'
def __init__(self, data_file, targetlist_file):
self.targets = np.recfromtxt(targetlist_file)
self.targets.dtype.names = target_names
self.dataF = tarfile.open(data_file)
self.ids = np.array(list(map(self._name_to_id, self.dataF.getnames())))
# rearrange targets so lists are in the same order
self.targets = self.targets[self.targets['objectID'].argsort()]
ind = self.targets['objectID'].searchsorted(self.ids)
self.targets = self.targets[ind]
def get_light_curve(self, id):
"""Get a light curve with the given id.
Parameters
----------
id: integer
LINEAR id of the desired object
Returns
-------
lightcurve: ndarray
a size (n_observations, 3) light-curve.
columns are [MJD, flux, flux_err]
"""
return self[id]
def get_target_parameter(self, id, param):
"""Get a target parameter associated with the given id.
Parameters
----------
id: integer
LINEAR id of the desired object
param: string
parameter name of the desired object (see below)
Returns
-------
val: scalar
value of the requested target parameter
Notes
-----
Target parameters are one of the following:
['objectID', 'raLIN', 'decLIN', 'raSDSS', 'decSDSS', 'r',
'ug', 'gr', 'ri', 'iz', 'JK', '<mL>', 'std', 'rms',
'Lchi2', 'LP1', 'phi1', 'S', 'prior']
"""
i = np.where(self.targets['objectID'] == id)[0]
try:
val = self.targets[param][i[0]]
except BaseException:
raise KeyError(id)
return val
def __getitem__(self, id):
try:
lc = np.loadtxt(self.dataF.extractfile(self._id_to_name(id)))
except BaseException:
raise KeyError(id)
return lc
[docs]def fetch_LINEAR_sample(data_home=None, download_if_missing=True):
"""Loader for LINEAR data sample
Parameters
----------
data_home : optional, default=None
Specify another download and cache folder for the datasets. By default
all astroML data is stored in '~/astroML_data'.
download_if_missing : optional, default=True
If False, raise a IOError if the data is not locally available
instead of trying to download the data from the source site.
Returns
-------
data : LINEARdata object
A custom object which provides access to 7010 selected LINEAR light
curves.
"""
data_home = get_data_home(data_home)
targetlist_file = os.path.join(data_home, os.path.basename(TARGETLIST_URL))
data_file = os.path.join(data_home, os.path.basename(DATA_URL))
if not os.path.exists(targetlist_file):
if not download_if_missing:
raise IOError('data not present on disk. '
'set download_if_missing=True to download')
targets = download_with_progress_bar(TARGETLIST_URL)
open(targetlist_file, 'wb').write(targets)
if not os.path.exists(data_file):
if not download_if_missing:
raise IOError('data not present on disk. '
'set download_if_missing=True to download')
databuffer = download_with_progress_bar(DATA_URL)
open(data_file, 'wb').write(databuffer)
return LINEARdata(data_file, targetlist_file)
[docs]def fetch_LINEAR_geneva(data_home=None, download_if_missing=True):
"""Loader for LINEAR geneva data.
This supplements the LINEAR data above with well-determined periods
and other light curve characteristics.
Parameters
----------
data_home : optional, default=None
Specify another download and cache folder for the datasets. By default
all astroML data is stored in '~/astroML_data'.
download_if_missing : optional, default=True
If False, raise a IOError if the data is not locally available
instead of trying to download the data from the source site.
Returns
-------
data : record array
data on 7000+ LINEAR stars from the Geneva catalog
"""
data_home = get_data_home(data_home)
archive_file = os.path.join(data_home, GENEVA_ARCHIVE)
if not os.path.exists(archive_file):
if not download_if_missing:
raise IOError('data not present on disk. '
'set download_if_missing=True to download')
data = Table.read(GENEVA_URL, format='ascii', header_start=19)
data = data.as_array()
np.save(archive_file, data)
else:
data = np.load(archive_file)
return data
