import math


def round_vzeros(v,d=10) :
    """Returns input vector with rounded to zero components
       which precision less than requested number of digits.
    """
    prec = pow(10,-d)
    vx = v[0] if math.fabs(v[0]) > prec else 0.0
    vy = v[1] if math.fabs(v[1]) > prec else 0.0
    vz = v[2] if math.fabs(v[2]) > prec else 0.0
    return vx,vy,vz