Adding horizontal lines as markers on time series subplots

Hi,

I made a plot that consists of 3 subplots, but I would like to add an arbitrary number of horizontal segments across all the subplots at different time indices. How do I do that? Alternatively, is there a way to directly click on the plot to generate these lines interactively?

trace0 = go.Scatter(x=curve0,y=y,mode=‘lines’,line=dict(shape=‘spline’))
trace1 = go.Scatter(x=curve1,y=y,mode=‘lines’,line=dict(shape=‘spline’))
trace2 = pgo.Scatter(x=curve2,y=y,mode=‘lines’,line=dict(shape=‘spline’))

fig = ply.tools.make_subplots(rows=1,cols=3,shared_yaxes=True)

fig.append_trace(trace0,1,1)
fig.append_trace(trace1,1,2)
fig.append_trace(trace2,1,3)

fig[‘layout’].update(title=‘Model’, height=1200, width=600, showlegend=False,
yaxis=dict(title=‘time’,autorange=‘reversed’))
py.offline.iplot(fig)