import numpy as np
import holoviews as hv
from holoviews import opts

hv.extension('matplotlib')

xs = np.random.normal(size=100)
ys = np.random.normal(size=100) * xs
points = hv.Points((xs,ys))

(points * hv.HLine(ys.mean())).opts(
    opts.HLine(color='blue', linewidth=6),
    opts.Points(color='#D3D3D3'))