# input file for nbody code
#    lines beginning with comment chars '#' are ignored
#    blank lines are also ignored
#
# the 'nbody' line describes the number of bodies in simulation
nbody 2

# duration of the simulation (years)
duration 5.00        

# time step (seconds)
#    in some future versions, this might change during the run
#    if the program decides that the error is too large ...
timestep  3600.0

# what is the interval between printing positions of each body
#    to the output file?
#    The units are seconds
print_interval 93600.0

# should the simulator determine the center-of-mass velocity
#    of the system from initial conditions and then
#    modify all velocities so that the overall system center-of-mass
#    velocity is zero?  Either 'yes' or 'no'
recenter yes

# integration technique to use
#    we have codes to specify the method, such as 
#        E1
#    for "Euler's method, first order"
# If the main program does not recognize a code,
#    or if the code is not yet implemented, the 
#    program will simply stop
#
# method "E1" is Euler's method, first order, 
#    for both velocity and acceleration      
# method "E1a" is Euler's method, first order, 
#    but use the new velocity to advance old position
# method "E2" is Euler's method, second order
#    also known as Heun's method
# method "RK4" is fourth-order Runge-Kutta
technique E2

# name of file into which we write output
#    can use "-" to write to stdout
#outfile -
outfile ./nbody.out

# now a series of lines, one per body
#    each line has format
#   
#     body  index   name  mass  px py pz  vx vy vz 
# 
#    where
#        body          is the string "body"       
#        index         is a count, starting at 0
#        name          is the name of the object
#        mass          is mass in kg
#        px  py  pz    are starting positions in m
#        vx  vy  vz    are starting velocities in m/s
#
#    Example:
# 
#        body   0  sun   1.99E30   0.0 0.0 0.0    0.0 0.0 0.0
#
body   0  sun      1.9891E30    0.0E0     0.0E0    0.0E0     0.0E0    0.00E0   0.0E0 
#body   1  earth    5.9742E24    1.50E11   0.0E0    0.0E0     0.0E0    2.97E4   0.0E0
body   1  sun2     1.9891E30    1.50E11   0.0E0    0.0E0     0.0E0    4.27E4   0.0E0

