本文整理匯總了Python中PyKEP.fb_vel方法的典型用法代碼示例。如果您正苦於以下問題：Python PyKEP.fb_vel方法的具體用法？Python PyKEP.fb_vel怎麽用？Python PyKEP.fb_vel使用的例子？那麽, 這裏精選的方法代碼示例或許可以為您提供幫助。您也可以進一步了解該方法所在類PyKEP的用法示例。
在下文中一共展示了PyKEP.fb_vel方法的1個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的Python代碼示例。
示例1: lambert_leg
# 需要導入模塊: import PyKEP [as 別名]
# 或者: from PyKEP import fb_vel [as 別名]
def lambert_leg(P1, P2, i, j, t1, t2, tof, vrel=None, dv_launch=0., rendezvous=False):
"""Compute a lambert leg from planet to planet.
Arguments:
p1 -- starting planet (str or PyKEP.planet object)
p2 -- final planet (str or PyKEP.planet object)
t0 -- start time of leg in MJD2000
tof -- time of flight in days
Keyword arguments:
vrel -- caresian coordinates of the relative velocity before the flyby at p1
dv_launch -- dv discounted at lunch (i.e. if vrel is None)
rendezvous -- add final dv
Returns:
dV, vrel_out, where vrel_out is the relative velocity at the end of the leg at p2
"""
p1 = PLANETS[str(P1)]
p2 = PLANETS[str(P2)]
r1 = state_rosetta.EPH[i][t1][0]
v1 = state_rosetta.EPH[i][t1][1]
r2 = state_rosetta.EPH[j][t2][0]
v2 = state_rosetta.EPH[j][t2][1]
lambert = kep.lambert_problem(r1, r2, tof * kep.DAY2SEC, p1.mu_central_body, False, 0)
vrel_in = tuple(map(lambda x, y: x - y, lambert.get_v1()[0], v1))
vrel_out = tuple(map(lambda x, y: x - y, lambert.get_v2()[0], v2))
if vrel is None:
# launch
dv = max(np.linalg.norm(vrel_in) - dv_launch, 0)
else:
# flyby
#print p1.name, p2.name, np.linalg.norm(vrel_in), np.linalg.norm(vrel_out)
dv = kep.fb_vel(vrel, vrel_in, p1)
if rendezvous:
dv += np.linalg.norm(vrel_out)
return dv, vrel_out