# -*- 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 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 .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']
__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]
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':
mcls._registry[cls.name] = cls
if 'subfmts' in members:
cls.subfmts = _regexify_subfmts(members['subfmts'])
return cls
[docs]class TimeJD(TimeFormat):
"""
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'
[docs] def set_jds(self, val1, val2):
self._check_scale(self._scale) # Validate scale.
self.jd1, self.jd2 = day_frac(val1, val2)
@property
def value(self):
return self.jd1 + self.jd2
[docs]class TimeMJD(TimeFormat):
"""
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'
[docs] def set_jds(self, val1, val2):
# TODO - this routine and vals should be Cythonized to follow the ERFA
# convention of preserving precision by adding to the larger of the two
# values in a vectorized operation. But in most practical cases the
# first one is probably biggest.
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)
@property
def value(self):
return (self.jd1 - erfa.DJM0) + self.jd2
[docs]class TimeDecimalYear(TimeFormat):
"""
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'
[docs] 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)
@property
def value(self):
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)
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 decimalyear
[docs]class TimeFromEpoch(TimeFormat):
"""
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)
[docs] 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 '{0}' epoch scale '{1}'"
"to specified scale '{2}', got error:\n{3}"
.format(self.name, self.epoch_scale,
self.scale, err))
self.jd1, self.jd2 = day_frac(tm._time.jd1, tm._time.jd2)
[docs] def to_value(self, parent=None):
# 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 '{0}' epoch scale '{1}'"
"to specified scale '{2}', got error:\n{3}"
.format(self.name, self.epoch_scale,
self.scale, err))
jd1, jd2 = tm._time.jd1, tm._time.jd2
else:
jd1, jd2 = self.jd1, self.jd2
time_from_epoch = ((jd1 - self.epoch.jd1) +
(jd2 - self.epoch.jd2)) / self.unit
return self.mask_if_needed(time_from_epoch)
value = property(to_value)
[docs]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'
[docs]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'
[docs]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 http://tycho.usno.navy.mil/gpstt.html
"""
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'
[docs]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'
[docs]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 {0} 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])
else:
val = getattr(val1_0, scale)._time
jd1, jd2 = val.jd1, val.jd2
OutTimeFormat = val1_0._time.__class__
self = OutTimeFormat(jd1, jd2, scale, precision, in_subfmt, out_subfmt,
from_jd=True)
return self
[docs]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):
# Note: don't care about val2 for this class
if not all(isinstance(val, datetime.datetime) for val in val1.flat):
raise TypeError('Input values for {0} class must be '
'datetime objects'.format(self.name))
return val1, None
[docs] 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'],
op_dtypes=[object] + 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)
[docs] def to_value(self, timezone=None, parent=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 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'],
op_dtypes=7*[iys.dtype] + [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)
[docs]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 : string, `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))
[docs] def utcoffset(self, dt):
return self._utcoffset
[docs] def tzname(self, dt):
return str(self._tzname)
[docs] def dst(self, dt):
return self._dst
[docs]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):
# Note: don't care about val2 for these classes
if val1.dtype.kind not in ('S', 'U'):
raise TypeError('Input values for {0} class must be strings'
.format(self.name))
return val1, None
[docs] 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 {0} does not match {1} format'
.format(timestr, self.name))
[docs] 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],
op_dtypes=[val1.dtype] + 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)
[docs] 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]):
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}
@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)
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('No subformats match {0}'.format(pattern))
return subfmts
[docs]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}'))
[docs] 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)
[docs]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}'))
[docs]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}'))
[docs]class TimeDatetime64(TimeISOT):
name = 'datetime64'
def _check_val_type(self, val1, val2):
# Note: don't care about val2 for this class`
if not val1.dtype.kind == 'M':
raise TypeError('Input values for {0} class must be '
'datetime64 objects'.format(self.name))
return val1, None
[docs] 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')
[docs]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)
[docs] 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 {0} does not match {1} 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 {0!r} is not in the allowed scales {1}"
.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 {0} 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.min() < 1721425.5 or jd.max() >= 5373484.5:
self.out_subfmt = 'long' + self.out_subfmt
return super().value
[docs]class TimeEpochDate(TimeFormat):
"""
Base class for support floating point Besselian and Julian epoch dates
"""
[docs] 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)
@property
def value(self):
jd_to_epoch = getattr(erfa, self.jd_to_epoch)
return jd_to_epoch(self.jd1, self.jd2)
[docs]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. ")
return super()._check_val_type(val1, val2)
[docs]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'
[docs]class TimeEpochDateString(TimeString):
"""
Base class to support string Besselian and Julian epoch dates
such as 'B1950.0' or 'J2000.0' respectively.
"""
[docs] 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])
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 {0} does not match {1} 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)
[docs]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'
[docs]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
[docs]class TimeDeltaSec(TimeDeltaFormat):
"""Time delta in SI seconds"""
name = 'sec'
unit = 1. / erfa.DAYSEC # for quantity input
[docs]class TimeDeltaJD(TimeDeltaFormat):
"""Time delta in Julian days (86400 SI seconds)"""
name = 'jd'
unit = 1.
[docs]class TimeDeltaDatetime(TimeDeltaFormat, TimeUnique):
"""Time delta in datetime.timedelta"""
name = 'datetime'
def _check_val_type(self, val1, val2):
# Note: don't care about val2 for this class
if not all(isinstance(val, datetime.timedelta) for val in val1.flat):
raise TypeError('Input values for {0} class must be '
'datetime.timedelta objects'.format(self.name))
return val1, None
[docs] def set_jds(self, val1, val2):
self._check_scale(self._scale) # Validate scale.
iterator = np.nditer([val1, None],
flags=['refs_ok'],
op_dtypes=[object] + [np.double])
for val, sec in iterator:
sec[...] = val.item().total_seconds()
self.jd1, self.jd2 = day_frac(iterator.operands[-1], 0.0,
divisor=erfa.DAYSEC)
@property
def value(self):
iterator = np.nditer([self.jd1 + self.jd2, None],
flags=['refs_ok'],
op_dtypes=[self.jd1.dtype] + [object])
for jd, out in iterator:
out[...] = datetime.timedelta(days=jd.item())
return self.mask_if_needed(iterator.operands[-1])
from .core import Time, TIME_SCALES, TIME_DELTA_SCALES, ScaleValueError