def __init__(self, a, f):
"""
Construct a Geodesic object for ellipsoid with major radius a and
flattening f.
"""
self._a = float(a)
self._f = float(f) if f <= 1 else 1.0/f
self._f1 = 1 - self._f
self._e2 = self._f * (2 - self._f)
self._ep2 = self._e2 / Math.sq(self._f1) # e2 / (1 - e2)
self._n = self._f / ( 2 - self._f)
self._b = self._a * self._f1
# authalic radius squared
self._c2 = (Math.sq(self._a) + Math.sq(self._b) *
(1 if self._e2 == 0 else
(Math.atanh(math.sqrt(self._e2)) if self._e2 > 0 else
math.atan(math.sqrt(-self._e2))) /
math.sqrt(abs(self._e2))))/2
self._etol2 = Geodesic.tol2_ / max(0.1, math.sqrt(abs(self._e2)))
if not(Math.isfinite(self._a) and self._a > 0):
raise ValueError("Major radius is not positive")
if not(Math.isfinite(self._b) and self._b > 0):
raise ValueError("Minor radius is not positive")
self._A3x = list(range(int(Geodesic.nA3x_)))
self._C3x = list(range(int(Geodesic.nC3x_)))
self._C4x = list(range(int(Geodesic.nC4x_)))
self.A3coeff()
self.C3coeff()
self.C4coeff()
def CheckDistance(s):
if not (Math.isfinite(s)):
raise ValueError("distance " + str(s) + " not a finite number")
