def d2yxu(self, i, j):
'''Return distance squared, points[i] to -[j] deltas and
longitudinal unrollment.
'''
p1 = self.pts[i]
p2 = self.pts[j]
return equirectangular_(p1.lat, p1.lon, p2.lat, p2.lon, **self.options)
def distance2(self, other, radius=R_M, adjust=False, wrap=False):
'''Compute the distance between this and an other geohash
using the U{Equirectangular Approximation / Projection
<http://www.movable-type.co.uk/scripts/latlong.html>}.
@param other: The other geohash (L{Geohash}).
@keyword radius: Optional, mean earth radius (meter) or None.
@keyword adjust: Adjust the wrapped, unrolled longitudinal
delta by the cosine of the mean latitude (bool).
@keyword wrap: Wrap and unroll longitudes (bool).
@return: Approximate distance (meter, same units as I{radius})
or distance squared (degrees squared) if I{radius}
is None or 0.
@raise TypeError: The I{other} is not a L{Geohash}, I{LatLon}
or str.
'''
other = _2Geohash(other)
a1, b1 = self.latlon
a2, b2 = other.latlon
if radius:
return equirectangular(a1, b1, a2, b2, radius=radius,
adjust=adjust, limit=None, wrap=wrap)
else:
return equirectangular_(a1, b1, a2, b2,
adjust=adjust, limit=None, wrap=wrap)[0]
def equirectangular3(lat1, lon1, lat2, lon2, **options):
'''For backward compatibility only, obsolete, replaced by
function L{utils.equirectangular_}.
See function L{utils.equirectangular_} for more details,
the available I{options} and errors raised.
@return: 3-Tuple (distance2, delta_lat, delta_lon).
'''
return utils.equirectangular_(lat1, lon1, lat2, lon2, **options)[:3]
def _degs(n, pts, closed): # angular edge lengths in degrees
u = 0 # previous x2's unroll/wrap
if closed:
j, i = 0, n-1
else:
j, i = 1, 0
x1, y1, _ = pts[i]
for i in range(j, n):
x2, y2, _ = pts[i]
# apply previous x2's unroll/wrap to new x1
d2, _, _, u = equirectangular_(y1, x1 + u, y2, x2,
adjust=adjust,
limit=None,
wrap=wrap)
yield sqrt(d2)
x1, y1 = x2, y2
def _d2yx(p2, p1, u):
# equirectangular_ returns a 4-tuple (distance in
# degrees squared, delta lat, delta lon, p2.lon
# unroll/wrap); the previous p2.lon unroll/wrap
# is also applied to the next edge's p1.lon
return equirectangular_(p1.lat, p1.lon + u, p2.lat, p2.lon, **options)