projektAI/venv/Lib/site-packages/matplotlib/testing/jpl_units/Epoch.py

233 lines
6.2 KiB
Python
Raw Normal View History

2021-06-06 22:13:05 +02:00
"""Epoch module."""
import operator
import math
import datetime as DT
from matplotlib import _api
from matplotlib.dates import date2num
class Epoch:
# Frame conversion offsets in seconds
# t(TO) = t(FROM) + allowed[ FROM ][ TO ]
allowed = {
"ET": {
"UTC": +64.1839,
},
"UTC": {
"ET": -64.1839,
},
}
def __init__(self, frame, sec=None, jd=None, daynum=None, dt=None):
"""
Create a new Epoch object.
Build an epoch 1 of 2 ways:
Using seconds past a Julian date:
# Epoch('ET', sec=1e8, jd=2451545)
or using a matplotlib day number
# Epoch('ET', daynum=730119.5)
= ERROR CONDITIONS
- If the input units are not in the allowed list, an error is thrown.
= INPUT VARIABLES
- frame The frame of the epoch. Must be 'ET' or 'UTC'
- sec The number of seconds past the input JD.
- jd The Julian date of the epoch.
- daynum The matplotlib day number of the epoch.
- dt A python datetime instance.
"""
if ((sec is None and jd is not None) or
(sec is not None and jd is None) or
(daynum is not None and
(sec is not None or jd is not None)) or
(daynum is None and dt is None and
(sec is None or jd is None)) or
(daynum is not None and dt is not None) or
(dt is not None and (sec is not None or jd is not None)) or
((dt is not None) and not isinstance(dt, DT.datetime))):
raise ValueError(
"Invalid inputs. Must enter sec and jd together, "
"daynum by itself, or dt (must be a python datetime).\n"
"Sec = %s\n"
"JD = %s\n"
"dnum= %s\n"
"dt = %s" % (sec, jd, daynum, dt))
_api.check_in_list(self.allowed, frame=frame)
self._frame = frame
if dt is not None:
daynum = date2num(dt)
if daynum is not None:
# 1-JAN-0001 in JD = 1721425.5
jd = float(daynum) + 1721425.5
self._jd = math.floor(jd)
self._seconds = (jd - self._jd) * 86400.0
else:
self._seconds = float(sec)
self._jd = float(jd)
# Resolve seconds down to [ 0, 86400)
deltaDays = math.floor(self._seconds / 86400)
self._jd += deltaDays
self._seconds -= deltaDays * 86400.0
def convert(self, frame):
if self._frame == frame:
return self
offset = self.allowed[self._frame][frame]
return Epoch(frame, self._seconds + offset, self._jd)
def frame(self):
return self._frame
def julianDate(self, frame):
t = self
if frame != self._frame:
t = self.convert(frame)
return t._jd + t._seconds / 86400.0
def secondsPast(self, frame, jd):
t = self
if frame != self._frame:
t = self.convert(frame)
delta = t._jd - jd
return t._seconds + delta * 86400
def __eq__(self, rhs):
return self._cmp(rhs, operator.eq)
def __ne__(self, rhs):
return self._cmp(rhs, operator.ne)
def __lt__(self, rhs):
return self._cmp(rhs, operator.lt)
def __le__(self, rhs):
return self._cmp(rhs, operator.le)
def __gt__(self, rhs):
return self._cmp(rhs, operator.gt)
def __ge__(self, rhs):
return self._cmp(rhs, operator.ge)
def _cmp(self, rhs, op):
"""
Compare two Epoch's.
= INPUT VARIABLES
- rhs The Epoch to compare against.
- op The function to do the comparison
= RETURN VALUE
- Returns op(self, rhs)
"""
t = self
if self._frame != rhs._frame:
t = self.convert(rhs._frame)
if t._jd != rhs._jd:
return op(t._jd, rhs._jd)
return op(t._seconds, rhs._seconds)
def __add__(self, rhs):
"""
Add a duration to an Epoch.
= INPUT VARIABLES
- rhs The Epoch to subtract.
= RETURN VALUE
- Returns the difference of ourselves and the input Epoch.
"""
t = self
if self._frame != rhs.frame():
t = self.convert(rhs._frame)
sec = t._seconds + rhs.seconds()
return Epoch(t._frame, sec, t._jd)
def __sub__(self, rhs):
"""
Subtract two Epoch's or a Duration from an Epoch.
Valid:
Duration = Epoch - Epoch
Epoch = Epoch - Duration
= INPUT VARIABLES
- rhs The Epoch to subtract.
= RETURN VALUE
- Returns either the duration between to Epoch's or the a new
Epoch that is the result of subtracting a duration from an epoch.
"""
# Delay-load due to circular dependencies.
import matplotlib.testing.jpl_units as U
# Handle Epoch - Duration
if isinstance(rhs, U.Duration):
return self + -rhs
t = self
if self._frame != rhs._frame:
t = self.convert(rhs._frame)
days = t._jd - rhs._jd
sec = t._seconds - rhs._seconds
return U.Duration(rhs._frame, days*86400 + sec)
def __str__(self):
"""Print the Epoch."""
return "%22.15e %s" % (self.julianDate(self._frame), self._frame)
def __repr__(self):
"""Print the Epoch."""
return str(self)
@staticmethod
def range(start, stop, step):
"""
Generate a range of Epoch objects.
Similar to the Python range() method. Returns the range [
start, stop) at the requested step. Each element will be a
Epoch object.
= INPUT VARIABLES
- start The starting value of the range.
- stop The stop value of the range.
- step Step to use.
= RETURN VALUE
- Returns a list containing the requested Epoch values.
"""
elems = []
i = 0
while True:
d = start + i * step
if d >= stop:
break
elems.append(d)
i += 1
return elems