def _get_swathsegment(filelist, time_start, time_end=None, area=None):
"""
Return only the granule files for the time interval or area.
"""
if area is not None:
from trollsched.spherical import SphPolygon
from trollsched.boundary import AreaBoundary
lons, lats = area.get_boundary_lonlats()
area_boundary = AreaBoundary(
(lons.side1, lats.side1), (lons.side2, lats.side2),
(lons.side3, lats.side3), (lons.side4, lats.side4))
area_boundary.decimate(500)
contour_poly = area_boundary.contour_poly
segment_files = []
for filename in filelist:
timetup = _get_times_from_npp(filename)
# Search for multiple granules using an area
if area is not None:
md = NPPMetaData(filename)
md.read()
coords = np.vstack(md.get_ring_lonlats())
poly = SphPolygon(np.deg2rad(coords))
if poly.intersection(contour_poly) is not None:
segment_files.append(filename)
continue
# Search for single granule using time start
if time_end is None:
if time_start >= timetup[0] and time_start <= timetup[1]:
segment_files.append(filename)
continue
# search for multiple granules
else:
# check that granule start time is inside interval
if timetup[0] >= time_start and timetup[0] <= time_end:
segment_files.append(filename)
continue
# check that granule end time is inside interval
if timetup[1] >= time_start and timetup[1] <= time_end:
segment_files.append(filename)
continue
segment_files.sort()
return segment_files
