def LoadMPC(self, **par):
"""
Input: boolean conditions for sampling.
Output: allocate a masked dictionary of orbital parameters from MPC catalogue.
"""
from os import path
from boolean_module import boolist
from packdesig import convert_design as conv_desig
# Loading the MPC catalogue from gzip compression.
if path.isfile(path.join("catalogues", "MPC_ORBITS.gz")):
import gzip
MPC = gzip.open(path.join("catalogues", "MPC_ORBITS.gz"), "r")
else:
from urllib2 import urlopen
MPC = urlopen("http://www.minorplanetcenter.net/iau/MPCORB/MPCORB.DAT", timeout=30)
asteroid = dict()
n = 0
for ast in MPC.readlines():
n += 1
if n > 41:
try:
tested_conditions = boolist(
par,
H=float(ast[8:12]),
G=float(ast[15:19]),
a=float(ast[93:103]),
e=float(ast[70:79]),
i=float(ast[59:68]),
)
if all(tested_conditions):
asteroid[conv_desig(ast[:7])] = tuple(ast[8:104].split())
except ValueError:
try:
tested_conditions = boolist(par, a=float(ast[93:103]), e=float(ast[70:79]), i=float(ast[59:68]))
if all(tested_conditions):
asteroid[conv_desig(ast[:7])] = tuple([0e0, 0.15] + ast[20:104].split())
except ValueError:
# print("Null entry in the line ",n," of the MPC catalogue........continue")
pass
print(
"\n MPC catalogue has been read. The total of asteroids fullfilling the conditions are ",
len(asteroid),
" of ",
n - 43,
)
# setting in self:
self.asteroid = asteroid
def Sampling(self, datestart=None, datestop=None, typetime="hour", parse=2, **limits):
"""
This method conducts a query through ephemeris of MPC asteroid catalogue sampling objects
within a date range and phase angle interval.
"""
from module import vmag, phase_angle, SeqDates, float_ra
from boolean_methods import boolist
degrees = ephem.degrees
here = self.here
# dates
if datestart is None and datestop is None:
datestart = NOW
datestop = NOW + datedelta.relativedelta(days=+1)
# range of dates.
dates = SeqDates(datestart, datestop, typetime, parse)
# designations
designation = dict.viewkeys(self.asteroid)
obj_ephem = {ast: self.LoadObject(ast) for ast in designation}
query = dict() # Dictionary
attendant = dict()
for date in dates:
date = str(date)
query[date] = dict() # Dictionary inside Dictionary
here.date = date
for ast in designation:
obj = obj_ephem[ast]
obj.compute(here) # Ephemeris for the date
angle = phase_angle(obj.elong, obj.earth_distance, obj.sun_distance, here)
mag = vmag(obj._H, obj._G, angle, obj.sun_distance, obj.earth_distance)
airmass = round(1e0 / cos(pi / 4e0 - float(obj.alt)), 4)
tested_conditions = boolist(
limits,
ph=angle,
r=obj.sun_distance,
mag=mag,
alt=degrees(float(obj.alt)),
airmass=airmass,
az=degrees(float(obj.az)),
ra=float_ra(obj.a_ra),
dec=degrees(float(obj.a_dec)),
)
if all(tested_conditions) and obj.alt >= here.horizon:
query[date][ast] = {
"phase angle": round(angle, 3),
"vmag": round(mag, 3),
"solar distance": obj.sun_distance,
"ra": str(obj.a_ra),
"dec": str(obj.a_dec),
"alt": str(obj.alt),
"airmass": airmass,
"az": str(obj.az),
} # Dictionary inside Dictionary inside Dictionary
if attendant.has_key(ast) == False:
attendant[ast] = {"dates": list()}
attendant[ast]["dates"].append(date)
# setting in self
self.attendant = attendant
self.query = query
print("There are ", len(dict.viewkeys(attendant)), " asteroids satisfying this query.")
