def _plot_timedep_vels(vels, labels, title=None):
    """Plot trial time-dependent velocities"""
    traces = list()
    for vel, label in zip(vels, labels):
        trace = dict(y=vel, text=label, name=label, hoverinfo='x+y+text')
        traces.append(trace)
    layout = dict(title=title, xaxis=dict(title='% of trial', automargin=
        True), yaxis=dict(title='Velocity (m/s)'))
    return dict(data=traces, layout=layout)
