def test_single_position(self):
with SPK(NAIF_DAF(open('de405.bsp', 'rb'))) as kernel:
x, y, z = kernel[0, 4].compute(2457061.5)
# Expect rough agreement with a DE430 position from our README:
self.assertAlmostEqual(x, 2.05700211e+08, delta=2.0)
self.assertAlmostEqual(y, 4.25141646e+07, delta=2.0)
self.assertAlmostEqual(z, 1.39379183e+07, delta=2.0)
def bsp_expiration(fileobj):
"""
Return the expiration date for a .bsp file.
"""
daf_object = DAF(fileobj)
spk_object = SPK(daf_object)
dates = [segment.end_jd for segment in spk_object.segments]
# We take the closest end date, to expire the file as soon as it's obsolete
end_jd = min(dates)
return calendar_date(end_jd)
def __init__(self, file):
if isinstance(file, str):
file = open(file, 'rb')
self.spk = SPK(file)
segments = [Segment(s.center, s.target, _build_compute(s))
for s in self.spk.segments]
codes = set(s.center for s in segments).union(
s.target for s in segments)
for code in codes:
body = Body(code, segments)
self[code] = body
raw_name = target_names.get(code, None)
if raw_name is None:
continue
name = raw_name.lower().replace(' ', '_')
setattr(self, name, body)
def get_summary(url, spk=True):
''' simple function to retrieve the header of a BSP file and return SPK object'''
# connect to file at URL
bspurl = urllib2.urlopen(url)
# retrieve the "tip" of a file at URL
bsptip = bspurl.read(10**5) # first 100kB
# save data in fake file object (in-memory)
bspstr = StringIO(bsptip)
# load into DAF object
daf = DAF(bspstr)
# return either SPK or DAF object
if spk:
# make a SPK object
spk = SPK(daf)
# return representation
return spk
else:
# return representation
return daf
