# Licensed under a 3-clause BSD style license - see LICENSE.rst
"""
Tools for scheduling observations.
"""
from __future__ import (absolute_import, division, print_function,
unicode_literals)
import copy
from abc import ABCMeta, abstractmethod
import numpy as np
from astropy import units as u
from astropy.time import Time
from astropy.table import Table
from .utils import time_grid_from_range, stride_array
from .constraints import AltitudeConstraint
from .target import get_skycoord
__all__ = ['ObservingBlock', 'TransitionBlock', 'Schedule', 'Slot',
'Scheduler', 'SequentialScheduler', 'PriorityScheduler',
'Transitioner', 'Scorer']
[docs]class ObservingBlock(object):
"""
An observation to be scheduled, consisting of a target and associated
constraints on observations.
"""
@u.quantity_input(duration=u.second)
def __init__(self, target, duration, priority, configuration={}, constraints=None):
"""
Parameters
----------
target : `~astroplan.FixedTarget`
Target to observe
duration : `~astropy.units.Quantity`
exposure time
priority : integer or float
priority of this object in the target list. 1 is highest priority,
no maximum
configuration : dict
Configuration metadata
constraints : list of `~astroplan.constraints.Constraint` objects
The constraints to apply to this particular observing block. Note
that constraints applicable to the entire list should go into the
scheduler.
"""
self.target = target
self.duration = duration
self.priority = priority
self.configuration = configuration
self.constraints = constraints
self.start_time = self.end_time = None
self.observer = None
def __repr__(self):
orig_repr = object.__repr__(self)
if self.start_time is None or self.end_time is None:
return orig_repr.replace('object at',
'({0}, unscheduled) at'
.format(self.target.name))
else:
s = '({0}, {1} to {2}) at'.format(self.target.name, self.start_time.iso,
self.end_time.iso)
return orig_repr.replace('object at', s)
@property
def constraints_scores(self):
if not (self.start_time and self.duration):
return None
# TODO: setup a way of caching or defining it as an attribute during scheduling
elif self.observer:
return {constraint: constraint(self.observer, self.target,
times=[self.start_time, self.start_time + self.duration])
for constraint in self.constraints}
[docs] @classmethod
def from_exposures(cls, target, priority, time_per_exposure,
number_exposures, readout_time=0 * u.second,
configuration={}, constraints=None):
duration = number_exposures * (time_per_exposure + readout_time)
ob = cls(target, duration, priority, configuration, constraints)
ob.time_per_exposure = time_per_exposure
ob.number_exposures = number_exposures
ob.readout_time = readout_time
return ob
[docs]class Scorer(object):
"""
Returns scores and score arrays from the evaluation of constraints on
observing blocks
"""
def __init__(self, blocks, observer, schedule, global_constraints=[]):
"""
Parameters
----------
blocks : list of `~astroplan.scheduling.ObservingBlock` objects
list of blocks that need to be scored
observer : `~astroplan.Observer`
the observer
schedule : `~astroplan.scheduling.Schedule`
The schedule inside which the blocks should fit
global_constraints : list of `~astroplan.Constraint` objects
any ``Constraint`` that applies to all the blocks
"""
self.blocks = blocks
self.observer = observer
self.schedule = schedule
self.global_constraints = global_constraints
self.targets = get_skycoord([block.target for block in self.blocks])
[docs] def create_score_array(self, time_resolution=1*u.minute):
"""
this makes a score array over the entire schedule for all of the
blocks and each `~astroplan.Constraint` in the .constraints of
each block and in self.global_constraints.
Parameters
----------
time_resolution : `~astropy.units.Quantity`
the time between each scored time
Returns
-------
score_array : `~numpy.ndarray`
array with dimensions (# of blocks, schedule length/ ``time_resolution``
"""
start = self.schedule.start_time
end = self.schedule.end_time
times = time_grid_from_range((start, end), time_resolution)
score_array = np.ones((len(self.blocks), len(times)))
for i, block in enumerate(self.blocks):
# TODO: change the default constraints from None to []
if block.constraints:
for constraint in block.constraints:
applied_score = constraint(self.observer, block.target,
times=times)
score_array[i] *= applied_score
for constraint in self.global_constraints:
score_array *= constraint(self.observer, self.targets, times,
grid_times_targets=True)
return score_array
[docs] @classmethod
def from_start_end(cls, blocks, observer, start_time, end_time,
global_constraints=[]):
"""
for if you don't have a schedule/ aren't inside a scheduler
"""
dummy_schedule = Schedule(start_time, end_time)
sc = cls(blocks, observer, dummy_schedule, global_constraints)
return sc
[docs]class TransitionBlock(object):
"""
Parameterizes the "dead time", e.g. between observations, while the
telescope is slewing, instrument is reconfiguring, etc.
"""
def __init__(self, components, start_time=None):
"""
Parameters
----------
components : dict
A dictionary mapping the reason for an observation's dead time to
`~astropy.units.Quantity` objects with time units
start_time : `~astropy.units.Quantity`
Start time of observation
"""
self._components = None
self.duration = None
self.start_time = start_time
self.components = components
def __repr__(self):
orig_repr = object.__repr__(self)
comp_info = ', '.join(['{0}: {1}'.format(c, t)
for c, t in self.components.items()])
if self.start_time is None or self.end_time is None:
return orig_repr.replace('object at', ' ({0}, unscheduled) at'.format(comp_info))
else:
s = '({0}, {1} to {2}) at'.format(comp_info, self.start_time.iso, self.end_time.iso)
return orig_repr.replace('object at', s)
@property
def end_time(self):
return self.start_time + self.duration
@property
def components(self):
return self._components
@components.setter
def components(self, val):
duration = 0*u.second
for t in val.values():
duration += t
self._components = val
self.duration = duration
[docs] @classmethod
@u.quantity_input(duration=u.second)
def from_duration(cls, duration):
# for testing how to put transitions between observations during
# scheduling without considering the complexities of duration
tb = TransitionBlock({'duration': duration})
return tb
[docs]class Schedule(object):
"""
An object that represents a schedule, consisting of a list of
`~astroplan.scheduling.Slot` objects.
"""
# as currently written, there should be no consecutive unoccupied slots
# this should change to allow for more flexibility (e.g. dark slots, grey slots)
def __init__(self, start_time, end_time, constraints=None):
"""
Parameters
-----------
start_time : `~astropy.time.Time`
The starting time of the schedule; the start of your
observing window.
end_time : `~astropy.time.Time`
The ending time of the schedule; the end of your
observing window
constraints : sequence of `~astroplan.constraints.Constraint` s
these are constraints that apply to the entire schedule
"""
self.start_time = start_time
self.end_time = end_time
self.slots = [Slot(start_time, end_time)]
self.observer = None
def __repr__(self):
return ('Schedule containing ' + str(len(self.observing_blocks)) +
' observing blocks between ' + str(self.slots[0].start.iso) +
' and ' + str(self.slots[-1].end.iso))
@property
def observing_blocks(self):
return [slot.block for slot in self.slots if isinstance(slot.block, ObservingBlock)]
@property
def scheduled_blocks(self):
return [slot.block for slot in self.slots if slot.block]
@property
def open_slots(self):
return [slot for slot in self.slots if not slot.occupied]
[docs] def to_table(self, show_transitions=True, show_unused=False):
# TODO: allow different coordinate types
target_names = []
start_times = []
end_times = []
durations = []
ra = []
dec = []
config = []
for slot in self.slots:
if hasattr(slot.block, 'target'):
start_times.append(slot.start.iso)
end_times.append(slot.end.iso)
durations.append(slot.duration.to(u.minute).value)
target_names.append(slot.block.target.name)
ra.append(slot.block.target.ra)
dec.append(slot.block.target.dec)
config.append(slot.block.configuration)
elif show_transitions and slot.block:
start_times.append(slot.start.iso)
end_times.append(slot.end.iso)
durations.append(slot.duration.to(u.minute).value)
target_names.append('TransitionBlock')
ra.append('')
dec.append('')
changes = list(slot.block.components.keys())
if 'slew_time' in changes:
changes.remove('slew_time')
config.append(changes)
elif slot.block is None and show_unused:
start_times.append(slot.start.iso)
end_times.append(slot.end.iso)
durations.append(slot.duration.to(u.minute).value)
target_names.append('Unused Time')
ra.append('')
dec.append('')
config.append('')
return Table([target_names, start_times, end_times, durations,
u.Quantity(ra), u.Quantity(dec), config],
names=('target', 'start time (UTC)', 'end time (UTC)',
'duration (minutes)', 'ra', 'dec', 'configuration'))
[docs] def new_slots(self, slot_index, start_time, end_time):
"""
Create new slots by splitting a current slot.
Parameters
----------
slot_index : int
The index of the slot to split
start_time : `~astropy.time.Time`
The start time for the slot to create
end_time : `~astropy.time.Time`
The end time for the slot to create
Returns
-------
new_slots : list of `~astroplan.scheduling.Slot` s
The new slots created
"""
# this is intended to be used such that there aren't consecutive unoccupied slots
new_slots = self.slots[slot_index].split_slot(start_time, end_time)
return new_slots
[docs] def insert_slot(self, start_time, block):
"""
Insert a slot into schedule and associate a block to the new slot.
Parameters
----------
start_time : `~astropy.time.Time`
The start time for the new slot.
block : `~astroplan.scheduling.ObservingBlock`
The observing block to insert into new slot.
Returns
-------
slots : list of `~astroplan.scheduling.Slot` objects
The new slots in the schedule.
"""
# due to float representation, this will change block start time
# and duration by up to 1 second in order to fit in a slot
for j, slot in enumerate(self.slots):
if ((slot.start < start_time or abs(slot.start-start_time) < 1*u.second)
and (slot.end > start_time + 1*u.second)):
slot_index = j
if (block.duration - self.slots[slot_index].duration) > 1*u.second:
raise ValueError('longer block than slot')
elif self.slots[slot_index].end - block.duration < start_time:
start_time = self.slots[slot_index].end - block.duration
if abs((self.slots[slot_index].duration - block.duration)) < 1 * u.second:
# slot duration is very similar to block duration.
# force equality so block fits
block.duration = self.slots[slot_index].duration
start_time = self.slots[slot_index].start
end_time = self.slots[slot_index].end
elif abs(self.slots[slot_index].start - start_time) < 1*u.second:
# start time of block is very close to slot start time
# force equality to avoid tiny gaps
start_time = self.slots[slot_index].start
end_time = start_time + block.duration
elif abs(self.slots[slot_index].end - start_time - block.duration) < 1*u.second:
# end time is very close to slot end time
# force equality to avoid tiny gaps
end_time = self.slots[slot_index].end
else:
end_time = start_time + block.duration
if isinstance(block, ObservingBlock):
# TODO: make it shift observing/transition blocks to fill small amounts of open space
block.end_time = start_time+block.duration
earlier_slots = self.slots[:slot_index]
later_slots = self.slots[slot_index+1:]
block.start_time = start_time
new_slots = self.new_slots(slot_index, start_time, end_time)
for new_slot in new_slots:
if new_slot.middle:
new_slot.occupied = True
new_slot.block = block
self.slots = earlier_slots + new_slots + later_slots
return earlier_slots + new_slots + later_slots
[docs] def change_slot_block(self, slot_index, new_block=None):
"""
Change the block associated with a slot.
This is currently designed to work for TransitionBlocks in PriorityScheduler
The assumption is that the slot afterwards is open and that the start time
will remain the same.
If the block is changed to None, the slot is merged with the slot
afterwards to make a longer slot.
Parameters
----------
slot_index : int
The slot to edit
new_block : `~astroplan.scheduling.TransitionBlock`, default None
The new transition block to insert in this slot
"""
if self.slots[slot_index + 1].block:
raise IndexError('slot afterwards is full')
if new_block is not None:
new_end = self.slots[slot_index].start + new_block.duration
self.slots[slot_index].end = new_end
self.slots[slot_index].block = new_block
self.slots[slot_index + 1].start = new_end
return slot_index
else:
self.slots[slot_index + 1].start = self.slots[slot_index].start
del self.slots[slot_index]
return slot_index - 1
[docs]class Slot(object):
"""
A time slot consisting of a start and end time
"""
def __init__(self, start_time, end_time):
"""
Parameters
-----------
start_time : `~astropy.time.Time`
The starting time of the slot
end_time : `~astropy.time.Time`
The ending time of the slot
"""
self.start = start_time
self.end = end_time
self.occupied = False
self.middle = False
self.block = None
@property
def duration(self):
return self.end - self.start
[docs] def split_slot(self, early_time, later_time):
"""
Split this slot and insert a new one.
Will return the new slots created, which can either
be one, two or three slots depending on if there is
space remaining before or after the inserted slot.
Parameters
----------
early_time : `~astropy.time.Time`
The start time of the new slot to insert.
later_time : `~astropy.time.Time`
The end time of the new slot to insert.
"""
# check if the new slot would overwrite occupied/other slots
if self.occupied:
raise ValueError('slot is already occupied')
new_slot = Slot(early_time, later_time)
new_slot.middle = True
early_slot = Slot(self.start, early_time)
late_slot = Slot(later_time, self.end)
if early_time > self.start and later_time < self.end:
return [early_slot, new_slot, late_slot]
elif early_time > self.start:
return [early_slot, new_slot]
elif later_time < self.end:
return [new_slot, late_slot]
else:
return [new_slot]
[docs]class Scheduler(object):
"""
Schedule a set of `~astroplan.scheduling.ObservingBlock` objects
"""
__metaclass__ = ABCMeta
@u.quantity_input(gap_time=u.second, time_resolution=u.second)
def __init__(self, constraints, observer, transitioner=None,
gap_time=5*u.min, time_resolution=20*u.second):
"""
Parameters
----------
constraints : sequence of `~astroplan.constraints.Constraint`
The constraints to apply to *every* observing block. Note that
constraints for specific blocks can go on each block individually.
observer : `~astroplan.Observer`
The observer/site to do the scheduling for.
transitioner : `~astroplan.scheduling.Transitioner` (required)
The object to use for computing transition times between blocks.
Leaving it as ``None`` will cause an error.
gap_time : `~astropy.units.Quantity` with time units
The maximum length of time a transition between ObservingBlocks
could take.
time_resolution : `~astropy.units.Quantity` with time units
The smallest factor of time used in scheduling, all Blocks scheduled
will have a duration that is a multiple of it.
"""
self.constraints = constraints
self.observer = observer
self.transitioner = transitioner
if not hasattr(self.transitioner, '__call__'):
raise ValueError("A callable Transitioner is required")
self.gap_time = gap_time
self.time_resolution = time_resolution
[docs] def __call__(self, blocks, schedule):
"""
Schedule a set of `~astroplan.scheduling.ObservingBlock` objects.
Parameters
----------
blocks : list of `~astroplan.scheduling.ObservingBlock` objects
The observing blocks to schedule. Note that the input
`~astroplan.scheduling.ObservingBlock` objects will *not* be
modified - new ones will be created and returned.
schedule : `~astroplan.scheduling.Schedule` object
A schedule that the blocks will be scheduled in. At this time
the ``schedule`` must be empty, only defined by a start and
end time.
Returns
-------
schedule : `~astroplan.scheduling.Schedule`
A schedule objects which consists of `~astroplan.scheduling.Slot`
objects with and without populated ``block`` objects containing either
`~astroplan.scheduling.TransitionBlock` or `~astroplan.scheduling.ObservingBlock`
objects with populated ``start_time`` and ``end_time`` or ``duration`` attributes
"""
self.schedule = schedule
self.schedule.observer = self.observer
# these are *shallow* copies
copied_blocks = [copy.copy(block) for block in blocks]
schedule = self._make_schedule(copied_blocks)
return schedule
@abstractmethod
def _make_schedule(self, blocks):
"""
Does the actual business of scheduling. The ``blocks`` passed in should
have their ``start_time` and `end_time`` modified to reflect the
schedule. Any necessary `~astroplan.scheduling.TransitionBlock` should
also be added. Then the full set of blocks should be returned as a list
of blocks, along with a boolean indicating whether or not they have been
put in order already.
Parameters
----------
blocks : list of `~astroplan.scheduling.ObservingBlock` objects
Can be modified as it is already copied by ``__call__``
Returns
-------
schedule : `~astroplan.scheduling.Schedule`
A schedule objects which consists of `~astroplan.scheduling.Slot`
objects with and without populated ``block`` objects containing either
`~astroplan.scheduling.TransitionBlock` or `~astroplan.scheduling.ObservingBlock`
objects with populated ``start_time`` and ``end_time`` or ``duration`` attributes.
"""
raise NotImplementedError
# return schedule
[docs] @classmethod
@u.quantity_input(duration=u.second)
def from_timespan(cls, center_time, duration, **kwargs):
"""
Create a new instance of this class given a center time and duration.
Parameters
----------
center_time : `~astropy.time.Time`
Mid-point of time-span to schedule.
duration : `~astropy.units.Quantity` or `~astropy.time.TimeDelta`
Duration of time-span to schedule
"""
start_time = center_time - duration / 2.
end_time = center_time + duration / 2.
return cls(start_time, end_time, **kwargs)
[docs]class SequentialScheduler(Scheduler):
"""
A scheduler that does "stupid simple sequential scheduling". That is, it
simply looks at all the blocks, picks the best one, schedules it, and then
moves on.
"""
def __init__(self, *args, **kwargs):
super(SequentialScheduler, self).__init__(*args, **kwargs)
def _make_schedule(self, blocks):
pre_filled = np.array([[block.start_time, block.end_time] for
block in self.schedule.scheduled_blocks])
if len(pre_filled) == 0:
a = self.schedule.start_time
filled_times = Time([a - 1*u.hour, a - 1*u.hour,
a - 1*u.minute, a - 1*u.minute])
pre_filled = filled_times.reshape((2, 2))
else:
filled_times = Time(pre_filled.flatten())
pre_filled = filled_times.reshape((int(len(filled_times)/2), 2))
for b in blocks:
if b.constraints is None:
b._all_constraints = self.constraints
else:
b._all_constraints = self.constraints + b.constraints
# to make sure the scheduler has some constraint to work off of
# and to prevent scheduling of targets below the horizon
# TODO : change default constraints to [] and switch to append
if b._all_constraints is None:
b._all_constraints = [AltitudeConstraint(min=0 * u.deg)]
b.constraints = [AltitudeConstraint(min=0 * u.deg)]
elif not any(isinstance(c, AltitudeConstraint) for c in b._all_constraints):
b._all_constraints.append(AltitudeConstraint(min=0 * u.deg))
if b.constraints is None:
b.constraints = [AltitudeConstraint(min=0 * u.deg)]
else:
b.constraints.append(AltitudeConstraint(min=0 * u.deg))
b._duration_offsets = u.Quantity([0*u.second, b.duration/2,
b.duration])
b.observer = self.observer
current_time = self.schedule.start_time
while (len(blocks) > 0) and (current_time < self.schedule.end_time):
# first compute the value of all the constraints for each block
# given the current starting time
block_transitions = []
block_constraint_results = []
for b in blocks:
# first figure out the transition
if len(self.schedule.observing_blocks) > 0:
trans = self.transitioner(
self.schedule.observing_blocks[-1], b, current_time, self.observer)
else:
trans = None
block_transitions.append(trans)
transition_time = 0*u.second if trans is None else trans.duration
times = current_time + transition_time + b._duration_offsets
# make sure it isn't in a pre-filled slot
if (any((current_time < filled_times) & (filled_times < times[2])) or
any(abs(pre_filled.T[0]-current_time) < 1*u.second)):
block_constraint_results.append(0)
else:
constraint_res = []
for constraint in b._all_constraints:
constraint_res.append(constraint(
self.observer, b.target, times))
# take the product over all the constraints *and* times
block_constraint_results.append(np.prod(constraint_res))
# now identify the block that's the best
bestblock_idx = np.argmax(block_constraint_results)
if block_constraint_results[bestblock_idx] == 0.:
# if even the best is unobservable, we need a gap
current_time += self.gap_time
else:
# If there's a best one that's observable, first get its transition
trans = block_transitions.pop(bestblock_idx)
if trans is not None:
self.schedule.insert_slot(trans.start_time, trans)
current_time += trans.duration
# now assign the block itself times and add it to the schedule
newb = blocks.pop(bestblock_idx)
newb.start_time = current_time
current_time += newb.duration
newb.end_time = current_time
newb.constraints_value = block_constraint_results[bestblock_idx]
self.schedule.insert_slot(newb.start_time, newb)
return self.schedule
[docs]class PriorityScheduler(Scheduler):
"""
A scheduler that optimizes a prioritized list. That is, it
finds the best time for each ObservingBlock, in order of priority.
"""
def __init__(self, *args, **kwargs):
"""
"""
super(PriorityScheduler, self).__init__(*args, **kwargs)
def _get_filled_indices(self, times):
is_open_time = np.ones(len(times), bool)
# close times that are already filled
pre_filled = np.array([[block.start_time, block.end_time] for
block in self.schedule.scheduled_blocks if
isinstance(block, ObservingBlock)])
for start_end in pre_filled:
filled = np.where((start_end[0] < times) & (times < start_end[1]))
if len(filled[0]) > 0:
is_open_time[filled[0]] = False
is_open_time[min(filled[0]) - 1] = False
return is_open_time
def _make_schedule(self, blocks):
# Combine individual constraints with global constraints, and
# retrieve priorities from each block to define scheduling order
_all_times = []
_block_priorities = np.zeros(len(blocks))
# make sure we don't schedule below the horizon
if self.constraints is None:
self.constraints = [AltitudeConstraint(min=0 * u.deg)]
else:
self.constraints.append(AltitudeConstraint(min=0 * u.deg))
for i, b in enumerate(blocks):
b._duration_offsets = u.Quantity([0 * u.second, b.duration / 2, b.duration])
_block_priorities[i] = b.priority
_all_times.append(b.duration)
b.observer = self.observer
# Define a master schedule
# Generate grid of time slots, and a mask for previous observations
time_resolution = self.time_resolution
times = time_grid_from_range([self.schedule.start_time, self.schedule.end_time],
time_resolution=time_resolution)
# generate the score arrays for all of the blocks
scorer = Scorer(blocks, self.observer, self.schedule,
global_constraints=self.constraints)
score_array = scorer.create_score_array(time_resolution)
# Sort the list of blocks by priority
sorted_indices = np.argsort(_block_priorities)
unscheduled_blocks = []
# Compute the optimal observation time in priority order
for i in sorted_indices:
b = blocks[i]
# Compute possible observing times by combining object constraints
# with the master open times mask
constraint_scores = score_array[i]
# Add up the applied constraints to prioritize the best blocks
# And then remove any times that are already scheduled
is_open_time = self._get_filled_indices(times)
constraint_scores[~is_open_time] = 0
# Select the most optimal time
# calculate the number of time slots needed for this exposure
_stride_by = int(np.ceil(float(b.duration / time_resolution)))
# Stride the score arrays by that number
_strided_scores = stride_array(constraint_scores, _stride_by)
# Collapse the sub-arrays
# (run them through scorekeeper again? Just add them?
# If there's a zero anywhere in there, def. have to skip)
good = np.all(_strided_scores > 1e-5, axis=1)
sum_scores = np.zeros(len(_strided_scores))
sum_scores[good] = np.sum(_strided_scores[good], axis=1)
if np.all(constraint_scores == 0) or np.all(~good):
# No further calculation if no times meet the constraints
_is_scheduled = False
else:
# schedulable in principle, provided the transition
# does not prevent us from fitting it in.
# loop over valid times and see if it fits
# TODO: speed up by searching multiples of time resolution?
for idx in np.argsort(sum_scores)[::-1]:
if sum_scores[idx] <= 0.0:
# we've run through all optimal blocks
_is_scheduled = False
break
try:
start_time_idx = idx
new_start_time = times[start_time_idx]
# attempt to schedule block
_is_scheduled = self.attempt_insert_block(b, new_start_time, start_time_idx)
if _is_scheduled:
break
except IndexError:
# idx can extend past end of _strided_open_time
_is_scheduled = False
break
if not _is_scheduled:
unscheduled_blocks.append(b)
return self.schedule
[docs] def attempt_insert_block(self, b, new_start_time, start_time_idx):
# set duration to be exact multiple of time resolution
duration_indices = int(np.ceil(
float(b.duration / self.time_resolution)))
b.duration = duration_indices * self.time_resolution
# add 1 second to the start time to allow for scheduling at the start of a slot
slot_index = [q for q, slot in enumerate(self.schedule.slots)
if slot.start < new_start_time + 1*u.second < slot.end][0]
slots_before = self.schedule.slots[:slot_index]
slots_after = self.schedule.slots[slot_index + 1:]
# now check if there's a transition block where we want to go
# if so, we delete it. A new one will be added if needed
delete_this_block_first = False
if self.schedule.slots[slot_index].block:
if isinstance(self.schedule.slots[slot_index].block, ObservingBlock):
raise ValueError('block already occupied')
else:
delete_this_block_first = True
# no slots yet, so we should be fine to just shove this in
if not (slots_before or slots_after):
b.end_idx = start_time_idx + duration_indices
b.start_idx = start_time_idx
if b.constraints is None:
b.constraints = self.constraints
elif self.constraints is not None:
b.constraints = b.constraints + self.constraints
try:
self.schedule.insert_slot(new_start_time, b)
return True
except ValueError as error:
# this shouldn't ever happen
print('Failed to insert {} into schedule.\n{}'.format(
b.target.name, str(error)
))
return False
# Other slots exist, so now we have to see if it will fit
# if slots before or after, we need `TransitionBlock`s
tb_before = None
tb_before_already_exists = False
tb_after = None
if slots_before:
if isinstance(
self.schedule.slots[slot_index - 1].block, ObservingBlock):
# make a transitionblock
tb_before = self.transitioner(
self.schedule.slots[slot_index - 1].block, b,
self.schedule.slots[slot_index - 1].end, self.observer)
elif isinstance(self.schedule.slots[slot_index - 1].block, TransitionBlock):
tb_before = self.transitioner(
self.schedule.slots[slot_index - 2].block, b,
self.schedule.slots[slot_index - 2].end, self.observer)
tb_before_already_exists = True
if slots_after:
slot_offset = 2 if delete_this_block_first else 1
if isinstance(
self.schedule.slots[slot_index + slot_offset].block, ObservingBlock):
# make a transition object after the new ObservingBlock
tb_after = self.transitioner(
b, self.schedule.slots[slot_index + slot_offset].block,
new_start_time + b.duration, self.observer)
# tweak durations to exact multiple of time resolution
for block in (tb_before, tb_after):
if block is not None:
block.duration = self.time_resolution * int(
np.ceil(float(block.duration / self.time_resolution))
)
# if we want to shift the OBs to minimise gaps, here is
# where we should do it.
# Find the smallest shift (forward or backward) to close gap
# Check against tolerances (constraints must still be met)
# Shift if OK and update new_start_time and start_time_idx
# Now let's see if the block and transition can fit in the schedule
if slots_before:
# we're OK if the index at the end of the updated transition
# is less than or equal to `start_time_idx`
ob_offset = 2 if tb_before_already_exists else 1
previous_ob = self.schedule.slots[slot_index - ob_offset]
if tb_before:
transition_indices = int(tb_before.duration / self.time_resolution)
else:
transition_indices = 0
if start_time_idx < previous_ob.block.end_idx + transition_indices:
# cannot schedule
return False
if slots_after:
# we're OK if the index at end of OB (plus transition)
# is smaller than the start_index of the slot after
slot_offset = 2 if delete_this_block_first else 1
next_ob = self.schedule.slots[slot_index + slot_offset].block
end_idx = start_time_idx + duration_indices
if tb_after:
end_idx += int(tb_after.duration / self.time_resolution)
if end_idx >= next_ob.start_idx:
# cannot schedule
return False
# OK, we should be OK to schedule now!
try:
# delete this block if it's a TransitionBlock
if delete_this_block_first:
slot_index = self.schedule.change_slot_block(slot_index, new_block=None)
if tb_before and tb_before_already_exists:
self.schedule.change_slot_block(slot_index - 1, new_block=tb_before)
elif tb_before:
self.schedule.insert_slot(tb_before.start_time, tb_before)
elif tb_before_already_exists and not tb_before:
# we already have a TB here, but we no longer need it!
self.schedule.change_slot_block(slot_index-1, new_block=None)
b.end_idx = start_time_idx + duration_indices
b.start_idx = start_time_idx
if b.constraints is None:
b.constraints = self.constraints
elif self.constraints is not None:
b.constraints = b.constraints + self.constraints
self.schedule.insert_slot(new_start_time, b)
if tb_after:
self.schedule.insert_slot(tb_after.start_time, tb_after)
except ValueError as error:
# this shouldn't ever happen
print('Failed to insert {} (dur: {}) into schedule.\n{}\n{}'.format(
b.target.name, b.duration, new_start_time.iso, str(error)
))
return False
return True
[docs]class Transitioner(object):
"""
A class that defines how to compute transition times from one block to
another.
"""
u.quantity_input(slew_rate=u.deg/u.second)
def __init__(self, slew_rate=None, instrument_reconfig_times=None):
"""
Parameters
----------
slew_rate : `~astropy.units.Quantity` with angle/time units
The slew rate of the telescope
instrument_reconfig_times : dict of dicts or None
If not None, gives a mapping from property names to another
dictionary. The second dictionary maps 2-tuples of states to the
time it takes to transition between those states (as an
`~astropy.units.Quantity`), can also take a 'default' key
mapped to a default transition time.
"""
self.slew_rate = slew_rate
self.instrument_reconfig_times = instrument_reconfig_times
[docs] def __call__(self, oldblock, newblock, start_time, observer):
"""
Determines the amount of time needed to transition from one observing
block to another. This uses the parameters defined in
``self.instrument_reconfig_times``.
Parameters
----------
oldblock : `~astroplan.scheduling.ObservingBlock` or None
The initial configuration/target
newblock : `~astroplan.scheduling.ObservingBlock` or None
The new configuration/target to transition to
start_time : `~astropy.time.Time`
The time the transition should start
observer : `astroplan.Observer`
The observer at the time
Returns
-------
transition : `~astroplan.scheduling.TransitionBlock` or None
A transition to get from ``oldblock`` to ``newblock`` or `None` if
no transition is necessary
"""
components = {}
if (self.slew_rate is not None and (oldblock is not None) and (newblock is not None)):
# use the constraints cache for now, but should move that machinery
# to observer
from .constraints import _get_altaz
from .target import get_skycoord
if oldblock.target != newblock.target:
targets = get_skycoord([oldblock.target, newblock.target])
aaz = _get_altaz(start_time, observer, targets)['altaz']
sep = aaz[0].separation(aaz[1])
if sep/self.slew_rate > 1 * u.second:
components['slew_time'] = sep / self.slew_rate
if self.instrument_reconfig_times is not None:
components.update(self.compute_instrument_transitions(oldblock, newblock))
if components:
return TransitionBlock(components, start_time)
else:
return None
[docs] def compute_instrument_transitions(self, oldblock, newblock):
components = {}
for conf_name, old_conf in oldblock.configuration.items():
if conf_name in newblock.configuration:
conf_times = self.instrument_reconfig_times.get(conf_name,
None)
if conf_times is not None:
new_conf = newblock.configuration[conf_name]
ctime = conf_times.get((old_conf, new_conf), None)
def_time = conf_times.get('default', None)
if ctime is not None:
s = '{0}:{1} to {2}'.format(conf_name, old_conf,
new_conf)
components[s] = ctime
elif def_time is not None and not old_conf == new_conf:
s = '{0}:{1} to {2}'.format(conf_name, old_conf,
new_conf)
components[s] = def_time
return components