simulated data

def next_data():
    "simulated data"
    t0 = time.time()
    lt = time.localtime(t0)
    tmin, tsec = lt[4],lt[5]
    u = np.random.random()
    v = np.random.random()
    x = np.sin( (u + tsec)/3.0) + tmin/30. + v/5.0
    return t0, x