# -*- coding: utf-8 -*-
# Licensed under a 3-clause BSD style license - see LICENSE.rst
import fnmatch
import time
import re
import datetime
import warnings
from decimal import Decimal
from collections import OrderedDict, defaultdict
import numpy as np
from astropy.utils.decorators import lazyproperty
from astropy.utils.exceptions import AstropyDeprecationWarning
from astropy import units as u
from astropy import _erfa as erfa
from . import utils
from .utils import day_frac, quantity_day_frac, two_sum, two_product
__all__ = ['TimeFormat', 'TimeJD', 'TimeMJD', 'TimeFromEpoch', 'TimeUnix',
'TimeCxcSec', 'TimeGPS', 'TimeDecimalYear',
'TimePlotDate', 'TimeUnique', 'TimeDatetime', 'TimeString',
'TimeISO', 'TimeISOT', 'TimeFITS', 'TimeYearDayTime',
'TimeEpochDate', 'TimeBesselianEpoch', 'TimeJulianEpoch',
'TimeDeltaFormat', 'TimeDeltaSec', 'TimeDeltaJD',
'TimeEpochDateString', 'TimeBesselianEpochString',
'TimeJulianEpochString', 'TIME_FORMATS', 'TIME_DELTA_FORMATS',
'TimezoneInfo', 'TimeDeltaDatetime', 'TimeDatetime64', 'TimeYMDHMS',
'TimeNumeric', 'TimeDeltaNumeric']
__doctest_skip__ = ['TimePlotDate']
# These both get filled in at end after TimeFormat subclasses defined.
# Use an OrderedDict to fix the order in which formats are tried.
# This ensures, e.g., that 'isot' gets tried before 'fits'.
TIME_FORMATS = OrderedDict()
TIME_DELTA_FORMATS = OrderedDict()
# Translations between deprecated FITS timescales defined by
# Rots et al. 2015, A&A 574:A36, and timescales used here.
FITS_DEPRECATED_SCALES = {'TDT': 'tt', 'ET': 'tt',
'GMT': 'utc', 'UT': 'utc', 'IAT': 'tai'}
def _regexify_subfmts(subfmts):
"""
Iterate through each of the sub-formats and try substituting simple
regular expressions for the strptime codes for year, month, day-of-month,
hour, minute, second. If no % characters remain then turn the final string
into a compiled regex. This assumes time formats do not have a % in them.
This is done both to speed up parsing of strings and to allow mixed formats
where strptime does not quite work well enough.
"""
new_subfmts = []
for subfmt_tuple in subfmts:
subfmt_in = subfmt_tuple[1]
if isinstance(subfmt_in, str):
for strptime_code, regex in (('%Y', r'(?P<year>\d\d\d\d)'),
('%m', r'(?P<mon>\d{1,2})'),
('%d', r'(?P<mday>\d{1,2})'),
('%H', r'(?P<hour>\d{1,2})'),
('%M', r'(?P<min>\d{1,2})'),
('%S', r'(?P<sec>\d{1,2})')):
subfmt_in = subfmt_in.replace(strptime_code, regex)
if '%' not in subfmt_in:
subfmt_tuple = (subfmt_tuple[0],
re.compile(subfmt_in + '$'),
subfmt_tuple[2])
new_subfmts.append(subfmt_tuple)
return tuple(new_subfmts)
class TimeFormatMeta(type):
"""
Metaclass that adds `TimeFormat` and `TimeDeltaFormat` to the
`TIME_FORMATS` and `TIME_DELTA_FORMATS` registries, respectively.
"""
_registry = TIME_FORMATS
def __new__(mcls, name, bases, members):
cls = super().__new__(mcls, name, bases, members)
# Register time formats that have a name, but leave out astropy_time since
# it is not a user-accessible format and is only used for initialization into
# a different format.
if 'name' in members and cls.name != 'astropy_time':
# FIXME: check here that we're not introducing a collision with
# an existing method or attribute; problem is it could be either
# astropy.time.Time or astropy.time.TimeDelta, and at the point
# where this is run neither of those classes have necessarily been
# constructed yet.
if 'value' in members and not hasattr(members['value'], "fget"):
raise ValueError("If defined, 'value' must be a property")
mcls._registry[cls.name] = cls
if 'subfmts' in members:
cls.subfmts = _regexify_subfmts(members['subfmts'])
return cls
class TimeFormat(metaclass=TimeFormatMeta):
"""
Base class for time representations.
Parameters
----------
val1 : numpy ndarray, list, number, str, or bytes
Values to initialize the time or times. Bytes are decoded as ascii.
val2 : numpy ndarray, list, or number; optional
Value(s) to initialize the time or times. Only used for numerical
input, to help preserve precision.
scale : str
Time scale of input value(s)
precision : int
Precision for seconds as floating point
in_subfmt : str
Select subformat for inputting string times
out_subfmt : str
Select subformat for outputting string times
from_jd : bool
If true then val1, val2 are jd1, jd2
"""
_default_scale = 'utc' # As of astropy 0.4
subfmts = ()
def __init__(self, val1, val2, scale, precision,
in_subfmt, out_subfmt, from_jd=False):
self.scale = scale # validation of scale done later with _check_scale
self.precision = precision
self.in_subfmt = in_subfmt
self.out_subfmt = out_subfmt
self._jd1, self._jd2 = None, None
if from_jd:
self.jd1 = val1
self.jd2 = val2
else:
val1, val2 = self._check_val_type(val1, val2)
self.set_jds(val1, val2)
@property
def jd1(self):
return self._jd1
@jd1.setter
def jd1(self, jd1):
self._jd1 = _validate_jd_for_storage(jd1)
if self._jd2 is not None:
self._jd1, self._jd2 = _broadcast_writeable(self._jd1, self._jd2)
@property
def jd2(self):
return self._jd2
@jd2.setter
def jd2(self, jd2):
self._jd2 = _validate_jd_for_storage(jd2)
if self._jd1 is not None:
self._jd1, self._jd2 = _broadcast_writeable(self._jd1, self._jd2)
def __len__(self):
return len(self.jd1)
@property
def scale(self):
"""Time scale"""
self._scale = self._check_scale(self._scale)
return self._scale
@scale.setter
def scale(self, val):
self._scale = val
def mask_if_needed(self, value):
if self.masked:
value = np.ma.array(value, mask=self.mask, copy=False)
return value
@property
def mask(self):
if 'mask' not in self.cache:
self.cache['mask'] = np.isnan(self.jd2)
if self.cache['mask'].shape:
self.cache['mask'].flags.writeable = False
return self.cache['mask']
@property
def masked(self):
if 'masked' not in self.cache:
self.cache['masked'] = bool(np.any(self.mask))
return self.cache['masked']
@property
def jd2_filled(self):
return np.nan_to_num(self.jd2) if self.masked else self.jd2
@lazyproperty
def cache(self):
"""
Return the cache associated with this instance.
"""
return defaultdict(dict)
def _check_val_type(self, val1, val2):
"""Input value validation, typically overridden by derived classes"""
# val1 cannot contain nan, but val2 can contain nan
ok1 = (val1.dtype.kind == 'f' and val1.dtype.itemsize >= 8
and np.all(np.isfinite(val1)) or val1.size == 0)
ok2 = val2 is None or (
val2.dtype.kind == 'f' and val2.dtype.itemsize >= 8
and not np.any(np.isinf(val2))) or val2.size == 0
if not (ok1 and ok2):
raise TypeError('Input values for {} class must be finite doubles'
.format(self.name))
if getattr(val1, 'unit', None) is not None:
# Convert any quantity-likes to days first, attempting to be
# careful with the conversion, so that, e.g., large numbers of
# seconds get converted without loosing precision because
# 1/86400 is not exactly representable as a float.
val1 = u.Quantity(val1, copy=False)
if val2 is not None:
val2 = u.Quantity(val2, copy=False)
try:
val1, val2 = quantity_day_frac(val1, val2)
except u.UnitsError:
raise u.UnitConversionError(
"only quantities with time units can be "
"used to instantiate Time instances.")
# We now have days, but the format may expect another unit.
# On purpose, multiply with 1./day_unit because typically it is
# 1./erfa.DAYSEC, and inverting it recovers the integer.
# (This conversion will get undone in format's set_jds, hence
# there may be room for optimizing this.)
factor = 1. / getattr(self, 'unit', 1.)
if factor != 1.:
val1, carry = two_product(val1, factor)
carry += val2 * factor
val1, val2 = two_sum(val1, carry)
elif getattr(val2, 'unit', None) is not None:
raise TypeError('Cannot mix float and Quantity inputs')
if val2 is None:
val2 = np.zeros_like(val1)
def asarray_or_scalar(val):
"""
Remove ndarray subclasses since for jd1/jd2 we want a pure ndarray
or a Python or numpy scalar.
"""
return np.asarray(val) if isinstance(val, np.ndarray) else val
return asarray_or_scalar(val1), asarray_or_scalar(val2)
def _check_scale(self, scale):
"""
Return a validated scale value.
If there is a class attribute 'scale' then that defines the default /
required time scale for this format. In this case if a scale value was
provided that needs to match the class default, otherwise return
the class default.
Otherwise just make sure that scale is in the allowed list of
scales. Provide a different error message if `None` (no value) was
supplied.
"""
if scale is None:
scale = self._default_scale
if scale not in TIME_SCALES:
raise ScaleValueError("Scale value '{}' not in "
"allowed values {}"
.format(scale, TIME_SCALES))
return scale
def set_jds(self, val1, val2):
"""
Set internal jd1 and jd2 from val1 and val2. Must be provided
by derived classes.
"""
raise NotImplementedError
def to_value(self, parent=None, out_subfmt=None):
"""
Return time representation from internal jd1 and jd2 in specified
``out_subfmt``.
This is the base method that ignores ``parent`` and uses the ``value``
property to compute the output. This is done by temporarily setting
``self.out_subfmt`` and calling ``self.value``. This is required for
legacy Format subclasses prior to astropy 4.0 New code should instead
implement the value functionality in ``to_value()`` and then make the
``value`` property be a simple call to ``self.to_value()``.
Parameters
----------
parent : obj
Parent `~astropy.time.Time` object associated with this
`~astropy.time.TimeFormat` object
out_subfmt : str or `None`
Output subformt (use existing self.out_subfmt if `None`)
Returns
-------
value : numpy.array, numpy.ma.array
Array or masked array of formatted time representation values
"""
# Get value via ``value`` property, overriding out_subfmt temporarily if needed.
if out_subfmt is not None:
out_subfmt_orig = self.out_subfmt
try:
self.out_subfmt = out_subfmt
value = self.value
finally:
self.out_subfmt = out_subfmt_orig
else:
value = self.value
return self.mask_if_needed(value)
@property
def value(self):
raise NotImplementedError
def _select_subfmts(self, pattern):
"""
Return a list of subformats where name matches ``pattern`` using
fnmatch.
"""
fnmatchcase = fnmatch.fnmatchcase
subfmts = [x for x in self.subfmts if fnmatchcase(x[0], pattern)]
if len(subfmts) == 0:
raise ValueError(f'No subformats match {pattern}')
return subfmts
class TimeNumeric(TimeFormat):
subfmts = (
('float', np.float64, None, np.add),
('long', np.longdouble, utils.longdouble_to_twoval,
utils.twoval_to_longdouble),
('decimal', np.object_, utils.decimal_to_twoval,
utils.twoval_to_decimal),
('str', np.str_, utils.decimal_to_twoval, utils.twoval_to_string),
('bytes', np.bytes_, utils.bytes_to_twoval, utils.twoval_to_bytes),
)
def _check_val_type(self, val1, val2):
"""Input value validation, typically overridden by derived classes"""
if val1.dtype.kind == 'f':
val1, val2 = super()._check_val_type(val1, val2)
elif (val2 is not None
or not (val1.dtype.kind in 'US'
or (val1.dtype.kind == 'O'
and all(isinstance(v, Decimal) for v in val1.flat)))):
raise TypeError(
'for {} class, input should be doubles, string, or Decimal, '
'and second values are only allowed for doubles.'
.format(self.name))
val_dtype = (val1.dtype if val2 is None else
np.result_type(val1.dtype, val2.dtype))
subfmts = self._select_subfmts(self.in_subfmt)
for subfmt, dtype, convert, _ in subfmts:
if np.issubdtype(val_dtype, dtype):
break
else:
raise ValueError('input type not among selected sub-formats.')
if convert is not None:
try:
val1, val2 = convert(val1, val2)
except Exception:
raise TypeError(
'for {} class, input should be (long) doubles, string, '
'or Decimal, and second values are only allowed for '
'(long) doubles.'.format(self.name))
return val1, val2
def to_value(self, jd1=None, jd2=None, parent=None, out_subfmt=None):
"""
Return time representation from internal jd1 and jd2.
Subclasses that require ``parent`` or to adjust the jds should
override this method.
"""
# TODO: do this in metaclass.
if self.__class__.value.fget is not self.__class__.to_value:
return self.value
if jd1 is None:
jd1 = self.jd1
if jd2 is None:
jd2 = self.jd2
if out_subfmt is None:
out_subfmt = self.out_subfmt
subfmt = self._select_subfmts(out_subfmt)[0]
kwargs = {}
if subfmt[0] in ('str', 'bytes'):
unit = getattr(self, 'unit', 1)
digits = int(np.ceil(np.log10(unit / np.finfo(float).eps)))
# TODO: allow a way to override the format.
kwargs['fmt'] = f'.{digits}f'
value = subfmt[3](jd1, jd2, **kwargs)
return self.mask_if_needed(value)
value = property(to_value)
class TimeJD(TimeNumeric):
"""
Julian Date time format.
This represents the number of days since the beginning of
the Julian Period.
For example, 2451544.5 in JD is midnight on January 1, 2000.
"""
name = 'jd'
def set_jds(self, val1, val2):
self._check_scale(self._scale) # Validate scale.
self.jd1, self.jd2 = day_frac(val1, val2)
class TimeMJD(TimeNumeric):
"""
Modified Julian Date time format.
This represents the number of days since midnight on November 17, 1858.
For example, 51544.0 in MJD is midnight on January 1, 2000.
"""
name = 'mjd'
def set_jds(self, val1, val2):
self._check_scale(self._scale) # Validate scale.
jd1, jd2 = day_frac(val1, val2)
jd1 += erfa.DJM0 # erfa.DJM0=2400000.5 (from erfam.h).
self.jd1, self.jd2 = day_frac(jd1, jd2)
def to_value(self, **kwargs):
jd1 = self.jd1 - erfa.DJM0 # This cannot lose precision.
jd2 = self.jd2
return super().to_value(jd1=jd1, jd2=jd2, **kwargs)
value = property(to_value)
class TimeDecimalYear(TimeNumeric):
"""
Time as a decimal year, with integer values corresponding to midnight
of the first day of each year. For example 2000.5 corresponds to the
ISO time '2000-07-02 00:00:00'.
"""
name = 'decimalyear'
def set_jds(self, val1, val2):
self._check_scale(self._scale) # Validate scale.
sum12, err12 = two_sum(val1, val2)
iy_start = np.trunc(sum12).astype(int)
extra, y_frac = two_sum(sum12, -iy_start)
y_frac += extra + err12
val = (val1 + val2).astype(np.double)
iy_start = np.trunc(val).astype(int)
imon = np.ones_like(iy_start)
iday = np.ones_like(iy_start)
ihr = np.zeros_like(iy_start)
imin = np.zeros_like(iy_start)
isec = np.zeros_like(y_frac)
# Possible enhancement: use np.unique to only compute start, stop
# for unique values of iy_start.
scale = self.scale.upper().encode('ascii')
jd1_start, jd2_start = erfa.dtf2d(scale, iy_start, imon, iday,
ihr, imin, isec)
jd1_end, jd2_end = erfa.dtf2d(scale, iy_start + 1, imon, iday,
ihr, imin, isec)
t_start = Time(jd1_start, jd2_start, scale=self.scale, format='jd')
t_end = Time(jd1_end, jd2_end, scale=self.scale, format='jd')
t_frac = t_start + (t_end - t_start) * y_frac
self.jd1, self.jd2 = day_frac(t_frac.jd1, t_frac.jd2)
def to_value(self, **kwargs):
scale = self.scale.upper().encode('ascii')
iy_start, ims, ids, ihmsfs = erfa.d2dtf(scale, 0, # precision=0
self.jd1, self.jd2_filled)
imon = np.ones_like(iy_start)
iday = np.ones_like(iy_start)
ihr = np.zeros_like(iy_start)
imin = np.zeros_like(iy_start)
isec = np.zeros_like(self.jd1)
# Possible enhancement: use np.unique to only compute start, stop
# for unique values of iy_start.
scale = self.scale.upper().encode('ascii')
jd1_start, jd2_start = erfa.dtf2d(scale, iy_start, imon, iday,
ihr, imin, isec)
jd1_end, jd2_end = erfa.dtf2d(scale, iy_start + 1, imon, iday,
ihr, imin, isec)
# Trying to be precise, but more than float64 not useful.
dt = (self.jd1 - jd1_start) + (self.jd2 - jd2_start)
dt_end = (jd1_end - jd1_start) + (jd2_end - jd2_start)
decimalyear = iy_start + dt / dt_end
return super().to_value(jd1=decimalyear, jd2=np.float64(0.0), **kwargs)
value = property(to_value)
class TimeFromEpoch(TimeNumeric):
"""
Base class for times that represent the interval from a particular
epoch as a floating point multiple of a unit time interval (e.g. seconds
or days).
"""
def __init__(self, val1, val2, scale, precision,
in_subfmt, out_subfmt, from_jd=False):
self.scale = scale
# Initialize the reference epoch (a single time defined in subclasses)
epoch = Time(self.epoch_val, self.epoch_val2, scale=self.epoch_scale,
format=self.epoch_format)
self.epoch = epoch
# Now create the TimeFormat object as normal
super().__init__(val1, val2, scale, precision, in_subfmt, out_subfmt,
from_jd)
def set_jds(self, val1, val2):
"""
Initialize the internal jd1 and jd2 attributes given val1 and val2.
For an TimeFromEpoch subclass like TimeUnix these will be floats giving
the effective seconds since an epoch time (e.g. 1970-01-01 00:00:00).
"""
# Form new JDs based on epoch time + time from epoch (converted to JD).
# One subtlety that might not be obvious is that 1.000 Julian days in
# UTC can be 86400 or 86401 seconds. For the TimeUnix format the
# assumption is that every day is exactly 86400 seconds, so this is, in
# principle, doing the math incorrectly, *except* that it matches the
# definition of Unix time which does not include leap seconds.
# note: use divisor=1./self.unit, since this is either 1 or 1/86400,
# and 1/86400 is not exactly representable as a float64, so multiplying
# by that will cause rounding errors. (But inverting it as a float64
# recovers the exact number)
day, frac = day_frac(val1, val2, divisor=1. / self.unit)
jd1 = self.epoch.jd1 + day
jd2 = self.epoch.jd2 + frac
# Create a temporary Time object corresponding to the new (jd1, jd2) in
# the epoch scale (e.g. UTC for TimeUnix) then convert that to the
# desired time scale for this object.
#
# A known limitation is that the transform from self.epoch_scale to
# self.scale cannot involve any metadata like lat or lon.
try:
tm = getattr(Time(jd1, jd2, scale=self.epoch_scale,
format='jd'), self.scale)
except Exception as err:
raise ScaleValueError("Cannot convert from '{}' epoch scale '{}'"
"to specified scale '{}', got error:\n{}"
.format(self.name, self.epoch_scale,
self.scale, err)) from err
self.jd1, self.jd2 = day_frac(tm._time.jd1, tm._time.jd2)
def to_value(self, parent=None, **kwargs):
# Make sure that scale is the same as epoch scale so we can just
# subtract the epoch and convert
if self.scale != self.epoch_scale:
if parent is None:
raise ValueError('cannot compute value without parent Time object')
try:
tm = getattr(parent, self.epoch_scale)
except Exception as err:
raise ScaleValueError("Cannot convert from '{}' epoch scale '{}'"
"to specified scale '{}', got error:\n{}"
.format(self.name, self.epoch_scale,
self.scale, err)) from err
jd1, jd2 = tm._time.jd1, tm._time.jd2
else:
jd1, jd2 = self.jd1, self.jd2
# This factor is guaranteed to be exactly representable, which
# means time_from_epoch1 is calculated exactly.
factor = 1. / self.unit
time_from_epoch1 = (jd1 - self.epoch.jd1) * factor
time_from_epoch2 = (jd2 - self.epoch.jd2) * factor
return super().to_value(jd1=time_from_epoch1, jd2=time_from_epoch2, **kwargs)
value = property(to_value)
@property
def _default_scale(self):
return self.epoch_scale
class TimeUnix(TimeFromEpoch):
"""
Unix time: seconds from 1970-01-01 00:00:00 UTC.
For example, 946684800.0 in Unix time is midnight on January 1, 2000.
NOTE: this quantity is not exactly unix time and differs from the strict
POSIX definition by up to 1 second on days with a leap second. POSIX
unix time actually jumps backward by 1 second at midnight on leap second
days while this class value is monotonically increasing at 86400 seconds
per UTC day.
"""
name = 'unix'
unit = 1.0 / erfa.DAYSEC # in days (1 day == 86400 seconds)
epoch_val = '1970-01-01 00:00:00'
epoch_val2 = None
epoch_scale = 'utc'
epoch_format = 'iso'
class TimeCxcSec(TimeFromEpoch):
"""
Chandra X-ray Center seconds from 1998-01-01 00:00:00 TT.
For example, 63072064.184 is midnight on January 1, 2000.
"""
name = 'cxcsec'
unit = 1.0 / erfa.DAYSEC # in days (1 day == 86400 seconds)
epoch_val = '1998-01-01 00:00:00'
epoch_val2 = None
epoch_scale = 'tt'
epoch_format = 'iso'
class TimeGPS(TimeFromEpoch):
"""GPS time: seconds from 1980-01-06 00:00:00 UTC
For example, 630720013.0 is midnight on January 1, 2000.
Notes
=====
This implementation is strictly a representation of the number of seconds
(including leap seconds) since midnight UTC on 1980-01-06. GPS can also be
considered as a time scale which is ahead of TAI by a fixed offset
(to within about 100 nanoseconds).
For details, see https://www.usno.navy.mil/USNO/time/gps/usno-gps-time-transfer
"""
name = 'gps'
unit = 1.0 / erfa.DAYSEC # in days (1 day == 86400 seconds)
epoch_val = '1980-01-06 00:00:19'
# above epoch is the same as Time('1980-01-06 00:00:00', scale='utc').tai
epoch_val2 = None
epoch_scale = 'tai'
epoch_format = 'iso'
class TimePlotDate(TimeFromEpoch):
"""
Matplotlib `~matplotlib.pyplot.plot_date` input:
1 + number of days from 0001-01-01 00:00:00 UTC
This can be used directly in the matplotlib `~matplotlib.pyplot.plot_date`
function::
>>> import matplotlib.pyplot as plt
>>> jyear = np.linspace(2000, 2001, 20)
>>> t = Time(jyear, format='jyear', scale='utc')
>>> plt.plot_date(t.plot_date, jyear)
>>> plt.gcf().autofmt_xdate() # orient date labels at a slant
>>> plt.draw()
For example, 730120.0003703703 is midnight on January 1, 2000.
"""
# This corresponds to the zero reference time for matplotlib plot_date().
# Note that TAI and UTC are equivalent at the reference time.
name = 'plot_date'
unit = 1.0
epoch_val = 1721424.5 # Time('0001-01-01 00:00:00', scale='tai').jd - 1
epoch_val2 = None
epoch_scale = 'utc'
epoch_format = 'jd'
class TimeStardate(TimeFromEpoch):
"""
Stardate: date units from 2318-07-05 12:00:00 UTC.
For example, stardate 41153.7 is 00:52 on April 30, 2363.
See http://trekguide.com/Stardates.htm#TNG for calculations and reference points
"""
name = 'stardate'
unit = 0.397766856 # Stardate units per day
epoch_val = '2318-07-05 11:00:00' # Date and time of stardate 00000.00
epoch_val2 = None
epoch_scale = 'tai'
epoch_format = 'iso'
class TimeUnique(TimeFormat):
"""
Base class for time formats that can uniquely create a time object
without requiring an explicit format specifier. This class does
nothing but provide inheritance to identify a class as unique.
"""
class TimeAstropyTime(TimeUnique):
"""
Instantiate date from an Astropy Time object (or list thereof).
This is purely for instantiating from a Time object. The output
format is the same as the first time instance.
"""
name = 'astropy_time'
def __new__(cls, val1, val2, scale, precision,
in_subfmt, out_subfmt, from_jd=False):
"""
Use __new__ instead of __init__ to output a class instance that
is the same as the class of the first Time object in the list.
"""
val1_0 = val1.flat[0]
if not (isinstance(val1_0, Time) and all(type(val) is type(val1_0)
for val in val1.flat)):
raise TypeError('Input values for {} class must all be same '
'astropy Time type.'.format(cls.name))
if scale is None:
scale = val1_0.scale
if val1.shape:
vals = [getattr(val, scale)._time for val in val1]
jd1 = np.concatenate([np.atleast_1d(val.jd1) for val in vals])
jd2 = np.concatenate([np.atleast_1d(val.jd2) for val in vals])
# Collect individual location values and merge into a single location.
if any(tm.location is not None for tm in val1):
if any(tm.location is None for tm in val1):
raise ValueError('cannot concatenate times unless all locations '
'are set or no locations are set')
locations = []
for tm in val1:
location = np.broadcast_to(tm.location, tm._time.jd1.shape,
subok=True)
locations.append(np.atleast_1d(location))
# Once we no longer have to support NUMPY_LT_1_17, we can
# just write np.concatenate(locations). Right now, we
# effectively do what __array_function__ does directly.
location0 = locations[0]
unit = location0.unit
location = np.concatenate([location.to_value(unit)
for location in locations])
location = location0._new_view(location)
else:
location = None
else:
val = getattr(val1_0, scale)._time
jd1, jd2 = val.jd1, val.jd2
location = val1_0.location
OutTimeFormat = val1_0._time.__class__
self = OutTimeFormat(jd1, jd2, scale, precision, in_subfmt, out_subfmt,
from_jd=True)
# Make a temporary hidden attribute to transfer location back to the
# parent Time object where it needs to live.
self._location = location
return self
class TimeDatetime(TimeUnique):
"""
Represent date as Python standard library `~datetime.datetime` object
Example::
>>> from astropy.time import Time
>>> from datetime import datetime
>>> t = Time(datetime(2000, 1, 2, 12, 0, 0), scale='utc')
>>> t.iso
'2000-01-02 12:00:00.000'
>>> t.tt.datetime
datetime.datetime(2000, 1, 2, 12, 1, 4, 184000)
"""
name = 'datetime'
def _check_val_type(self, val1, val2):
if not all(isinstance(val, datetime.datetime) for val in val1.flat):
raise TypeError('Input values for {} class must be '
'datetime objects'.format(self.name))
if val2 is not None:
raise ValueError(
f'{self.name} objects do not accept a val2 but you provided {val2}')
return val1, None
def set_jds(self, val1, val2):
"""Convert datetime object contained in val1 to jd1, jd2"""
# Iterate through the datetime objects, getting year, month, etc.
iterator = np.nditer([val1, None, None, None, None, None, None],
flags=['refs_ok', 'zerosize_ok'],
op_dtypes=[None] + 5*[np.intc] + [np.double])
for val, iy, im, id, ihr, imin, dsec in iterator:
dt = val.item()
if dt.tzinfo is not None:
dt = (dt - dt.utcoffset()).replace(tzinfo=None)
iy[...] = dt.year
im[...] = dt.month
id[...] = dt.day
ihr[...] = dt.hour
imin[...] = dt.minute
dsec[...] = dt.second + dt.microsecond / 1e6
jd1, jd2 = erfa.dtf2d(self.scale.upper().encode('ascii'),
*iterator.operands[1:])
self.jd1, self.jd2 = day_frac(jd1, jd2)
def to_value(self, timezone=None, parent=None, out_subfmt=None):
"""
Convert to (potentially timezone-aware) `~datetime.datetime` object.
If ``timezone`` is not ``None``, return a timezone-aware datetime
object.
Parameters
----------
timezone : {`~datetime.tzinfo`, None}, optional
If not `None`, return timezone-aware datetime.
Returns
-------
`~datetime.datetime`
If ``timezone`` is not ``None``, output will be timezone-aware.
"""
if out_subfmt is not None:
# Out_subfmt not allowed for this format, so raise the standard
# exception by trying to validate the value.
self._select_subfmts(out_subfmt)
if timezone is not None:
if self._scale != 'utc':
raise ScaleValueError("scale is {}, must be 'utc' when timezone "
"is supplied.".format(self._scale))
# Rather than define a value property directly, we have a function,
# since we want to be able to pass in timezone information.
scale = self.scale.upper().encode('ascii')
iys, ims, ids, ihmsfs = erfa.d2dtf(scale, 6, # 6 for microsec
self.jd1, self.jd2_filled)
ihrs = ihmsfs['h']
imins = ihmsfs['m']
isecs = ihmsfs['s']
ifracs = ihmsfs['f']
iterator = np.nditer([iys, ims, ids, ihrs, imins, isecs, ifracs, None],
flags=['refs_ok', 'zerosize_ok'],
op_dtypes=7*[None] + [object])
for iy, im, id, ihr, imin, isec, ifracsec, out in iterator:
if isec >= 60:
raise ValueError('Time {} is within a leap second but datetime '
'does not support leap seconds'
.format((iy, im, id, ihr, imin, isec, ifracsec)))
if timezone is not None:
out[...] = datetime.datetime(iy, im, id, ihr, imin, isec, ifracsec,
tzinfo=TimezoneInfo()).astimezone(timezone)
else:
out[...] = datetime.datetime(iy, im, id, ihr, imin, isec, ifracsec)
return self.mask_if_needed(iterator.operands[-1])
value = property(to_value)
class TimeYMDHMS(TimeUnique):
"""
ymdhms: A Time format to represent Time as year, month, day, hour,
minute, second (thus the name ymdhms).
Acceptable inputs must have keys or column names in the "YMDHMS" set of
``year``, ``month``, ``day`` ``hour``, ``minute``, ``second``:
- Dict with keys in the YMDHMS set
- NumPy structured array, record array or astropy Table, or single row
of those types, with column names in the YMDHMS set
One can supply a subset of the YMDHMS values, for instance only 'year',
'month', and 'day'. Inputs have the following defaults::
'month': 1, 'day': 1, 'hour': 0, 'minute': 0, 'second': 0
When the input is supplied as a ``dict`` then each value can be either a
scalar value or an array. The values will be broadcast to a common shape.
Example::
>>> from astropy.time import Time
>>> t = Time({'year': 2015, 'month': 2, 'day': 3,
... 'hour': 12, 'minute': 13, 'second': 14.567},
... scale='utc')
>>> t.iso
'2015-02-03 12:13:14.567'
>>> t.ymdhms.year
2015
"""
name = 'ymdhms'
def _check_val_type(self, val1, val2):
"""
This checks inputs for the YMDHMS format.
It is bit more complex than most format checkers because of the flexible
input that is allowed. Also, it actually coerces ``val1`` into an appropriate
dict of ndarrays that can be used easily by ``set_jds()``. This is useful
because it makes it easy to get default values in that routine.
Parameters
----------
val1 : ndarray or None
val2 : ndarray or None
Returns
-------
val1_as_dict, val2 : val1 as dict or None, val2 is always None
"""
if val2 is not None:
raise ValueError('val2 must be None for ymdhms format')
ymdhms = ['year', 'month', 'day', 'hour', 'minute', 'second']
if val1.dtype.names:
# Convert to a dict of ndarray
val1_as_dict = {name: val1[name] for name in val1.dtype.names}
elif val1.shape == (0,):
# Input was empty list [], so set to None and set_jds will handle this
return None, None
elif (val1.dtype.kind == 'O'
and val1.shape == ()
and isinstance(val1.item(), dict)):
# Code gets here for input as a dict. The dict input
# can be either scalar values or N-d arrays.
# Extract the item (which is a dict) and broadcast values to the
# same shape here.
names = val1.item().keys()
values = val1.item().values()
val1_as_dict = {name: value for name, value
in zip(names, np.broadcast_arrays(*values))}
else:
raise ValueError('input must be dict or table-like')
# Check that the key names now are good.
names = val1_as_dict.keys()
required_names = ymdhms[:len(names)]
def comma_repr(vals):
return ', '.join(repr(val) for val in vals)
bad_names = set(names) - set(ymdhms)
if bad_names:
raise ValueError(f'{comma_repr(bad_names)} not allowed as YMDHMS key name(s)')
if set(names) != set(required_names):
raise ValueError(f'for {len(names)} input key names '
f'you must supply {comma_repr(required_names)}')
return val1_as_dict, val2
def set_jds(self, val1, val2):
if val1 is None:
# Input was empty list []
jd1 = np.array([], dtype=np.float64)
jd2 = np.array([], dtype=np.float64)
else:
jd1, jd2 = erfa.dtf2d(self.scale.upper().encode('ascii'),
val1['year'],
val1.get('month', 1),
val1.get('day', 1),
val1.get('hour', 0),
val1.get('minute', 0),
val1.get('second', 0))
self.jd1, self.jd2 = day_frac(jd1, jd2)
@property
def value(self):
scale = self.scale.upper().encode('ascii')
iys, ims, ids, ihmsfs = erfa.d2dtf(scale, 9,
self.jd1, self.jd2_filled)
out = np.empty(self.jd1.shape, dtype=[('year', 'i4'),
('month', 'i4'),
('day', 'i4'),
('hour', 'i4'),
('minute', 'i4'),
('second', 'f8')])
out['year'] = iys
out['month'] = ims
out['day'] = ids
out['hour'] = ihmsfs['h']
out['minute'] = ihmsfs['m']
out['second'] = ihmsfs['s'] + ihmsfs['f'] * 10**(-9)
out = out.view(np.recarray)
return self.mask_if_needed(out)
class TimezoneInfo(datetime.tzinfo):
"""
Subclass of the `~datetime.tzinfo` object, used in the
to_datetime method to specify timezones.
It may be safer in most cases to use a timezone database package like
pytz rather than defining your own timezones - this class is mainly
a workaround for users without pytz.
"""
@u.quantity_input(utc_offset=u.day, dst=u.day)
def __init__(self, utc_offset=0 * u.day, dst=0 * u.day, tzname=None):
"""
Parameters
----------
utc_offset : `~astropy.units.Quantity`, optional
Offset from UTC in days. Defaults to zero.
dst : `~astropy.units.Quantity`, optional
Daylight Savings Time offset in days. Defaults to zero
(no daylight savings).
tzname : str or `None`, optional
Name of timezone
Examples
--------
>>> from datetime import datetime
>>> from astropy.time import TimezoneInfo # Specifies a timezone
>>> import astropy.units as u
>>> utc = TimezoneInfo() # Defaults to UTC
>>> utc_plus_one_hour = TimezoneInfo(utc_offset=1*u.hour) # UTC+1
>>> dt_aware = datetime(2000, 1, 1, 0, 0, 0, tzinfo=utc_plus_one_hour)
>>> print(dt_aware)
2000-01-01 00:00:00+01:00
>>> print(dt_aware.astimezone(utc))
1999-12-31 23:00:00+00:00
"""
if utc_offset == 0 and dst == 0 and tzname is None:
tzname = 'UTC'
self._utcoffset = datetime.timedelta(utc_offset.to_value(u.day))
self._tzname = tzname
self._dst = datetime.timedelta(dst.to_value(u.day))
def utcoffset(self, dt):
return self._utcoffset
def tzname(self, dt):
return str(self._tzname)
def dst(self, dt):
return self._dst
class TimeString(TimeUnique):
"""
Base class for string-like time representations.
This class assumes that anything following the last decimal point to the
right is a fraction of a second.
This is a reference implementation can be made much faster with effort.
"""
def _check_val_type(self, val1, val2):
if val1.dtype.kind not in ('S', 'U') and val1.size:
raise TypeError('Input values for {} class must be strings'
.format(self.name))
if val2 is not None:
raise ValueError(
f'{self.name} objects do not accept a val2 but you provided {val2}')
return val1, None
def parse_string(self, timestr, subfmts):
"""Read time from a single string, using a set of possible formats."""
# Datetime components required for conversion to JD by ERFA, along
# with the default values.
components = ('year', 'mon', 'mday', 'hour', 'min', 'sec')
defaults = (None, 1, 1, 0, 0, 0)
# Assume that anything following "." on the right side is a
# floating fraction of a second.
try:
idot = timestr.rindex('.')
except Exception:
fracsec = 0.0
else:
timestr, fracsec = timestr[:idot], timestr[idot:]
fracsec = float(fracsec)
for _, strptime_fmt_or_regex, _ in subfmts:
if isinstance(strptime_fmt_or_regex, str):
try:
tm = time.strptime(timestr, strptime_fmt_or_regex)
except ValueError:
continue
else:
vals = [getattr(tm, 'tm_' + component)
for component in components]
else:
tm = re.match(strptime_fmt_or_regex, timestr)
if tm is None:
continue
tm = tm.groupdict()
vals = [int(tm.get(component, default)) for component, default
in zip(components, defaults)]
# Add fractional seconds
vals[-1] = vals[-1] + fracsec
return vals
else:
raise ValueError('Time {} does not match {} format'
.format(timestr, self.name))
def set_jds(self, val1, val2):
"""Parse the time strings contained in val1 and set jd1, jd2"""
# Select subformats based on current self.in_subfmt
subfmts = self._select_subfmts(self.in_subfmt)
# Be liberal in what we accept: convert bytes to ascii.
# Here .item() is needed for arrays with entries of unequal length,
# to strip trailing 0 bytes.
to_string = (str if val1.dtype.kind == 'U' else
lambda x: str(x.item(), encoding='ascii'))
iterator = np.nditer([val1, None, None, None, None, None, None],
flags=['zerosize_ok'],
op_dtypes=[None] + 5 * [np.intc] + [np.double])
for val, iy, im, id, ihr, imin, dsec in iterator:
val = to_string(val)
iy[...], im[...], id[...], ihr[...], imin[...], dsec[...] = (
self.parse_string(val, subfmts))
jd1, jd2 = erfa.dtf2d(self.scale.upper().encode('ascii'),
*iterator.operands[1:])
self.jd1, self.jd2 = day_frac(jd1, jd2)
def str_kwargs(self):
"""
Generator that yields a dict of values corresponding to the
calendar date and time for the internal JD values.
"""
scale = self.scale.upper().encode('ascii'),
iys, ims, ids, ihmsfs = erfa.d2dtf(scale, self.precision,
self.jd1, self.jd2_filled)
# Get the str_fmt element of the first allowed output subformat
_, _, str_fmt = self._select_subfmts(self.out_subfmt)[0]
if '{yday:' in str_fmt:
has_yday = True
else:
has_yday = False
yday = None
ihrs = ihmsfs['h']
imins = ihmsfs['m']
isecs = ihmsfs['s']
ifracs = ihmsfs['f']
for iy, im, id, ihr, imin, isec, ifracsec in np.nditer(
[iys, ims, ids, ihrs, imins, isecs, ifracs],
flags=['zerosize_ok']):
if has_yday:
yday = datetime.datetime(iy, im, id).timetuple().tm_yday
yield {'year': int(iy), 'mon': int(im), 'day': int(id),
'hour': int(ihr), 'min': int(imin), 'sec': int(isec),
'fracsec': int(ifracsec), 'yday': yday}
def format_string(self, str_fmt, **kwargs):
"""Write time to a string using a given format.
By default, just interprets str_fmt as a format string,
but subclasses can add to this.
"""
return str_fmt.format(**kwargs)
@property
def value(self):
# Select the first available subformat based on current
# self.out_subfmt
subfmts = self._select_subfmts(self.out_subfmt)
_, _, str_fmt = subfmts[0]
# TODO: fix this ugly hack
if self.precision > 0 and str_fmt.endswith('{sec:02d}'):
str_fmt += '.{fracsec:0' + str(self.precision) + 'd}'
# Try to optimize this later. Can't pre-allocate because length of
# output could change, e.g. year rolls from 999 to 1000.
outs = []
for kwargs in self.str_kwargs():
outs.append(str(self.format_string(str_fmt, **kwargs)))
return np.array(outs).reshape(self.jd1.shape)
class TimeISO(TimeString):
"""
ISO 8601 compliant date-time format "YYYY-MM-DD HH:MM:SS.sss...".
For example, 2000-01-01 00:00:00.000 is midnight on January 1, 2000.
The allowed subformats are:
- 'date_hms': date + hours, mins, secs (and optional fractional secs)
- 'date_hm': date + hours, mins
- 'date': date
"""
name = 'iso'
subfmts = (('date_hms',
'%Y-%m-%d %H:%M:%S',
# XXX To Do - use strftime for output ??
'{year:d}-{mon:02d}-{day:02d} {hour:02d}:{min:02d}:{sec:02d}'),
('date_hm',
'%Y-%m-%d %H:%M',
'{year:d}-{mon:02d}-{day:02d} {hour:02d}:{min:02d}'),
('date',
'%Y-%m-%d',
'{year:d}-{mon:02d}-{day:02d}'))
def parse_string(self, timestr, subfmts):
# Handle trailing 'Z' for UTC time
if timestr.endswith('Z'):
if self.scale != 'utc':
raise ValueError("Time input terminating in 'Z' must have "
"scale='UTC'")
timestr = timestr[:-1]
return super().parse_string(timestr, subfmts)
class TimeISOT(TimeISO):
"""
ISO 8601 compliant date-time format "YYYY-MM-DDTHH:MM:SS.sss...".
This is the same as TimeISO except for a "T" instead of space between
the date and time.
For example, 2000-01-01T00:00:00.000 is midnight on January 1, 2000.
The allowed subformats are:
- 'date_hms': date + hours, mins, secs (and optional fractional secs)
- 'date_hm': date + hours, mins
- 'date': date
"""
name = 'isot'
subfmts = (('date_hms',
'%Y-%m-%dT%H:%M:%S',
'{year:d}-{mon:02d}-{day:02d}T{hour:02d}:{min:02d}:{sec:02d}'),
('date_hm',
'%Y-%m-%dT%H:%M',
'{year:d}-{mon:02d}-{day:02d}T{hour:02d}:{min:02d}'),
('date',
'%Y-%m-%d',
'{year:d}-{mon:02d}-{day:02d}'))
class TimeYearDayTime(TimeISO):
"""
Year, day-of-year and time as "YYYY:DOY:HH:MM:SS.sss...".
The day-of-year (DOY) goes from 001 to 365 (366 in leap years).
For example, 2000:001:00:00:00.000 is midnight on January 1, 2000.
The allowed subformats are:
- 'date_hms': date + hours, mins, secs (and optional fractional secs)
- 'date_hm': date + hours, mins
- 'date': date
"""
name = 'yday'
subfmts = (('date_hms',
'%Y:%j:%H:%M:%S',
'{year:d}:{yday:03d}:{hour:02d}:{min:02d}:{sec:02d}'),
('date_hm',
'%Y:%j:%H:%M',
'{year:d}:{yday:03d}:{hour:02d}:{min:02d}'),
('date',
'%Y:%j',
'{year:d}:{yday:03d}'))
class TimeDatetime64(TimeISOT):
name = 'datetime64'
def _check_val_type(self, val1, val2):
if not val1.dtype.kind == 'M':
if val1.size > 0:
raise TypeError('Input values for {} class must be '
'datetime64 objects'.format(self.name))
else:
val1 = np.array([], 'datetime64[D]')
if val2 is not None:
raise ValueError(
f'{self.name} objects do not accept a val2 but you provided {val2}')
return val1, None
def set_jds(self, val1, val2):
# If there are any masked values in the ``val1`` datetime64 array
# ('NaT') then stub them with a valid date so downstream parse_string
# will work. The value under the mask is arbitrary but a "modern" date
# is good.
mask = np.isnat(val1)
masked = np.any(mask)
if masked:
val1 = val1.copy()
val1[mask] = '2000'
# Make sure M(onth) and Y(ear) dates will parse and convert to bytestring
if val1.dtype.name in ['datetime64[M]', 'datetime64[Y]']:
val1 = val1.astype('datetime64[D]')
val1 = val1.astype('S')
# Standard ISO string parsing now
super().set_jds(val1, val2)
# Finally apply mask if necessary
if masked:
self.jd2[mask] = np.nan
@property
def value(self):
precision = self.precision
self.precision = 9
ret = super().value
self.precision = precision
return ret.astype('datetime64')
class TimeFITS(TimeString):
"""
FITS format: "[±Y]YYYY-MM-DD[THH:MM:SS[.sss]]".
ISOT but can give signed five-digit year (mostly for negative years);
The allowed subformats are:
- 'date_hms': date + hours, mins, secs (and optional fractional secs)
- 'date': date
- 'longdate_hms': as 'date_hms', but with signed 5-digit year
- 'longdate': as 'date', but with signed 5-digit year
See Rots et al., 2015, A&A 574:A36 (arXiv:1409.7583).
"""
name = 'fits'
subfmts = (
('date_hms',
(r'(?P<year>\d{4})-(?P<mon>\d\d)-(?P<mday>\d\d)T'
r'(?P<hour>\d\d):(?P<min>\d\d):(?P<sec>\d\d(\.\d*)?)'),
'{year:04d}-{mon:02d}-{day:02d}T{hour:02d}:{min:02d}:{sec:02d}'),
('date',
r'(?P<year>\d{4})-(?P<mon>\d\d)-(?P<mday>\d\d)',
'{year:04d}-{mon:02d}-{day:02d}'),
('longdate_hms',
(r'(?P<year>[+-]\d{5})-(?P<mon>\d\d)-(?P<mday>\d\d)T'
r'(?P<hour>\d\d):(?P<min>\d\d):(?P<sec>\d\d(\.\d*)?)'),
'{year:+06d}-{mon:02d}-{day:02d}T{hour:02d}:{min:02d}:{sec:02d}'),
('longdate',
r'(?P<year>[+-]\d{5})-(?P<mon>\d\d)-(?P<mday>\d\d)',
'{year:+06d}-{mon:02d}-{day:02d}'))
# Add the regex that parses the scale and possible realization.
# Support for this is deprecated. Read old style but no longer write
# in this style.
subfmts = tuple(
(subfmt[0],
subfmt[1] + r'(\((?P<scale>\w+)(\((?P<realization>\w+)\))?\))?',
subfmt[2]) for subfmt in subfmts)
def parse_string(self, timestr, subfmts):
"""Read time and deprecated scale if present"""
# Try parsing with any of the allowed sub-formats.
for _, regex, _ in subfmts:
tm = re.match(regex, timestr)
if tm:
break
else:
raise ValueError('Time {} does not match {} format'
.format(timestr, self.name))
tm = tm.groupdict()
# Scale and realization are deprecated and strings in this form
# are no longer created. We issue a warning but still use the value.
if tm['scale'] is not None:
warnings.warn("FITS time strings should no longer have embedded time scale.",
AstropyDeprecationWarning)
# If a scale was given, translate from a possible deprecated
# timescale identifier to the scale used by Time.
fits_scale = tm['scale'].upper()
scale = FITS_DEPRECATED_SCALES.get(fits_scale, fits_scale.lower())
if scale not in TIME_SCALES:
raise ValueError("Scale {!r} is not in the allowed scales {}"
.format(scale, sorted(TIME_SCALES)))
# If no scale was given in the initialiser, set the scale to
# that given in the string. Realization is ignored
# and is only supported to allow old-style strings to be
# parsed.
if self._scale is None:
self._scale = scale
if scale != self.scale:
raise ValueError("Input strings for {} class must all "
"have consistent time scales."
.format(self.name))
return [int(tm['year']), int(tm['mon']), int(tm['mday']),
int(tm.get('hour', 0)), int(tm.get('min', 0)),
float(tm.get('sec', 0.))]
@property
def value(self):
"""Convert times to strings, using signed 5 digit if necessary."""
if 'long' not in self.out_subfmt:
# If we have times before year 0 or after year 9999, we can
# output only in a "long" format, using signed 5-digit years.
jd = self.jd1 + self.jd2
if jd.size and (jd.min() < 1721425.5 or jd.max() >= 5373484.5):
self.out_subfmt = 'long' + self.out_subfmt
return super().value
class TimeEpochDate(TimeNumeric):
"""
Base class for support floating point Besselian and Julian epoch dates
"""
_default_scale = 'tt' # As of astropy 3.2, this is no longer 'utc'.
def set_jds(self, val1, val2):
self._check_scale(self._scale) # validate scale.
epoch_to_jd = getattr(erfa, self.epoch_to_jd)
jd1, jd2 = epoch_to_jd(val1 + val2)
self.jd1, self.jd2 = day_frac(jd1, jd2)
def to_value(self, **kwargs):
jd_to_epoch = getattr(erfa, self.jd_to_epoch)
value = jd_to_epoch(self.jd1, self.jd2)
return super().to_value(jd1=value, jd2=np.float64(0.0), **kwargs)
value = property(to_value)
class TimeBesselianEpoch(TimeEpochDate):
"""Besselian Epoch year as floating point value(s) like 1950.0"""
name = 'byear'
epoch_to_jd = 'epb2jd'
jd_to_epoch = 'epb'
def _check_val_type(self, val1, val2):
"""Input value validation, typically overridden by derived classes"""
if hasattr(val1, 'to') and hasattr(val1, 'unit'):
raise ValueError("Cannot use Quantities for 'byear' format, "
"as the interpretation would be ambiguous. "
"Use float with Besselian year instead. ")
# FIXME: is val2 really okay here?
return super()._check_val_type(val1, val2)
class TimeJulianEpoch(TimeEpochDate):
"""Julian Epoch year as floating point value(s) like 2000.0"""
name = 'jyear'
unit = erfa.DJY # 365.25, the Julian year, for conversion to quantities
epoch_to_jd = 'epj2jd'
jd_to_epoch = 'epj'
class TimeEpochDateString(TimeString):
"""
Base class to support string Besselian and Julian epoch dates
such as 'B1950.0' or 'J2000.0' respectively.
"""
_default_scale = 'tt' # As of astropy 3.2, this is no longer 'utc'.
def set_jds(self, val1, val2):
epoch_prefix = self.epoch_prefix
# Be liberal in what we accept: convert bytes to ascii.
to_string = (str if val1.dtype.kind == 'U' else
lambda x: str(x.item(), encoding='ascii'))
iterator = np.nditer([val1, None], op_dtypes=[val1.dtype, np.double],
flags=['zerosize_ok'])
for val, years in iterator:
try:
time_str = to_string(val)
epoch_type, year_str = time_str[0], time_str[1:]
year = float(year_str)
if epoch_type.upper() != epoch_prefix:
raise ValueError
except (IndexError, ValueError, UnicodeEncodeError):
raise ValueError('Time {} does not match {} format'
.format(time_str, self.name))
else:
years[...] = year
self._check_scale(self._scale) # validate scale.
epoch_to_jd = getattr(erfa, self.epoch_to_jd)
jd1, jd2 = epoch_to_jd(iterator.operands[-1])
self.jd1, self.jd2 = day_frac(jd1, jd2)
@property
def value(self):
jd_to_epoch = getattr(erfa, self.jd_to_epoch)
years = jd_to_epoch(self.jd1, self.jd2)
# Use old-style format since it is a factor of 2 faster
str_fmt = self.epoch_prefix + '%.' + str(self.precision) + 'f'
outs = [str_fmt % year for year in years.flat]
return np.array(outs).reshape(self.jd1.shape)
class TimeBesselianEpochString(TimeEpochDateString):
"""Besselian Epoch year as string value(s) like 'B1950.0'"""
name = 'byear_str'
epoch_to_jd = 'epb2jd'
jd_to_epoch = 'epb'
epoch_prefix = 'B'
class TimeJulianEpochString(TimeEpochDateString):
"""Julian Epoch year as string value(s) like 'J2000.0'"""
name = 'jyear_str'
epoch_to_jd = 'epj2jd'
jd_to_epoch = 'epj'
epoch_prefix = 'J'
class TimeDeltaFormatMeta(TimeFormatMeta):
_registry = TIME_DELTA_FORMATS
class TimeDeltaFormat(TimeFormat, metaclass=TimeDeltaFormatMeta):
"""Base class for time delta representations"""
def _check_scale(self, scale):
"""
Check that the scale is in the allowed list of scales, or is `None`
"""
if scale is not None and scale not in TIME_DELTA_SCALES:
raise ScaleValueError("Scale value '{}' not in "
"allowed values {}"
.format(scale, TIME_DELTA_SCALES))
return scale
class TimeDeltaNumeric(TimeDeltaFormat, TimeNumeric):
def set_jds(self, val1, val2):
self._check_scale(self._scale) # Validate scale.
self.jd1, self.jd2 = day_frac(val1, val2, divisor=1. / self.unit)
def to_value(self, **kwargs):
# Note that 1/unit is always exactly representable, so the
# following multiplications are exact.
factor = 1. / self.unit
jd1 = self.jd1 * factor
jd2 = self.jd2 * factor
return super().to_value(jd1=jd1, jd2=jd2, **kwargs)
value = property(to_value)
class TimeDeltaSec(TimeDeltaNumeric):
"""Time delta in SI seconds"""
name = 'sec'
unit = 1. / erfa.DAYSEC # for quantity input
class TimeDeltaJD(TimeDeltaNumeric):
"""Time delta in Julian days (86400 SI seconds)"""
name = 'jd'
unit = 1.
class TimeDeltaDatetime(TimeDeltaFormat, TimeUnique):
"""Time delta in datetime.timedelta"""
name = 'datetime'
def _check_val_type(self, val1, val2):
if not all(isinstance(val, datetime.timedelta) for val in val1.flat):
raise TypeError('Input values for {} class must be '
'datetime.timedelta objects'.format(self.name))
if val2 is not None:
raise ValueError(
f'{self.name} objects do not accept a val2 but you provided {val2}')
return val1, None
def set_jds(self, val1, val2):
self._check_scale(self._scale) # Validate scale.
iterator = np.nditer([val1, None, None],
flags=['refs_ok', 'zerosize_ok'],
op_dtypes=[None, np.double, np.double])
day = datetime.timedelta(days=1)
for val, jd1, jd2 in iterator:
jd1[...], other = divmod(val.item(), day)
jd2[...] = other / day
self.jd1, self.jd2 = day_frac(iterator.operands[-2],
iterator.operands[-1])
@property
def value(self):
iterator = np.nditer([self.jd1, self.jd2, None],
flags=['refs_ok', 'zerosize_ok'],
op_dtypes=[None, None, object])
for jd1, jd2, out in iterator:
jd1_, jd2_ = day_frac(jd1, jd2)
out[...] = datetime.timedelta(days=jd1_,
microseconds=jd2_ * 86400 * 1e6)
return self.mask_if_needed(iterator.operands[-1])
def _validate_jd_for_storage(jd):
if isinstance(jd, (float, int)):
return np.array(jd, dtype=np.float_)
if (isinstance(jd, np.generic)
and (jd.dtype.kind == 'f' and jd.dtype.itemsize <= 8
or jd.dtype.kind in 'iu')):
return np.array(jd, dtype=np.float_)
elif (isinstance(jd, np.ndarray)
and jd.dtype.kind == 'f'
and jd.dtype.itemsize == 8):
return jd
else:
raise TypeError(
f"JD values must be arrays (possibly zero-dimensional) "
f"of floats but we got {jd!r} of type {type(jd)}")
def _broadcast_writeable(jd1, jd2):
if jd1.shape == jd2.shape:
return jd1, jd2
# When using broadcast_arrays, *both* are flagged with
# warn-on-write, even the one that wasn't modified, and
# require "C" only clears the flag if it actually copied
# anything.
shape = np.broadcast(jd1, jd2).shape
if jd1.shape == shape:
s_jd1 = jd1
else:
s_jd1 = np.require(np.broadcast_to(jd1, shape),
requirements=["C", "W"])
if jd2.shape == shape:
s_jd2 = jd2
else:
s_jd2 = np.require(np.broadcast_to(jd2, shape),
requirements=["C", "W"])
return s_jd1, s_jd2
from .core import Time, TIME_SCALES, TIME_DELTA_SCALES, ScaleValueError # noqa