Python Wrapper for ivlam

This is a python wrapper of the Fortran code of Russell's Lambert Solver.

Install

pip install ivlam

Usage

Initialize

from ivlam import *

infoload = ivlam.initialize(-1)
if(infoload!=0):
    print('Error in ivlam_initialize')

Solve the Problem

r1vec=np.array([1.0,2.0,3.0])  
r2vec=np.array([2.0,-3.0,-4.0])
tof=450.0

prograde=True
direction=ivlam.getdirection(prograde,r1vec,r2vec)

dimensionV=10
v1vec,v2vec,uptonhave,inforeturnstatusn,infohalfrevstatus = ivlam.thrun(r1vec,r2vec,tof,direction,dimensionV,dimensionV)
if(inforeturnstatusn!=0):
    print('Error in ivlam_thrun')
if(infohalfrevstatus!=0):
    print('This example is very close to the nPi transfer')
print(v1vec[:,dimensionV-uptonhave:dimensionV+uptonhave+1])
print(v2vec[:,dimensionV-uptonhave:dimensionV+uptonhave+1])

License

GNU General Public License v3 or later (GPLv3+)

Reference

[1] Russell, Ryan P., "On the Solution to Every Lambert Problem," Celestial Mechanics and Dynamical Astronomy, Vol. 131, Article 50, 2019, pp. 1-33, https://dx.doi.org/10.1007/s10569-019-9927-z

[2] Russell, Ryan P., "Complete Lambert Solver Including Second-Order Sensitivities," Journal of Guidance, Control, and Dynamics, accepted 2021, https://doi.org/10.2514/1.G006089