def METHOD_NAME(sel, eqsys=None):
    """
    Matplotlib cursor format for regular 1D plots.
    """
    x, y = sel.target
    rx = int(np.round(x))
    sx = 'x: {:d}'.format(rx)
    sy = 'y: {:.5e}'.format(y)
    if eqsys is not None:
        sx += ' ({})'.format(eqsys[rx].toxstring(rx))
    s = sx + '\n' + sy
    sel.annotation.set_text(s)