# version:  1
# ivar, variable_name, variable_type
 1, position_x, d
 2, position_y, d
 3, position_z, d
 4, velocity_x, d
 5, velocity_y, d
 6, velocity_z, d
 7, mass, d
 8, identity, i
 9, levelp, i
10, family, b
11, tag, b
12, birth_time, d
13, metallicity, d