def plot_b(Figs, araiblock, zijdblock, pars):
    """
    deprecated (used in thellier_magic/microwave_magic)
    """
    angle = zijdblock[0][1]
    plotblock = []
    Dir, zx, zy, zz, ax, ay = [], [], [], [], [], []
    zstart, zend = 0, len(zijdblock)
    first_Z, first_I = araiblock[0], araiblock[1]
    for rec in zijdblock:
        if rec[0] == pars["measurement_step_min"]:
            Dir.append((rec[1] - angle, rec[2],
                        old_div(rec[3], zijdblock[0][3])))
        if rec[0] == pars["measurement_step_max"]:
            Dir.append((rec[1] - angle, rec[2],
                        old_div(rec[3], zijdblock[0][3])))
    for drec in Dir:
        cart = pmag.dir2cart(drec)
        zx.append(cart[0])
      #   zy.append(-cart[1])
      #   zz.append(-cart[2])
        zy.append(cart[1])
        zz.append(cart[2])
    if len(zx) > 0:
        plt.figure(num=Figs['zijd'])
        plt.scatter(zx, zy, marker='d', s=100, c='y')
        plt.scatter(zx, zz, marker='d', s=100, c='y')
        plt.axis("equal")
    ax.append(old_div(first_I[0][3], first_Z[0][3]))
    ax.append(old_div(first_I[-1][3], first_Z[0][3]))
    ay.append(old_div(first_Z[0][3], first_Z[0][3]))
    ay.append(old_div(first_Z[-1][3], first_Z[0][3]))
    for k in range(len(first_Z)):
        if first_Z[k][0] == pars["measurement_step_min"]:
            ay[0] = (old_div(first_Z[k][3], first_Z[0][3]))
        if first_Z[k][0] == pars["measurement_step_max"]:
            ay[1] = (old_div(first_Z[k][3], first_Z[0][3]))
        if first_I[k][0] == pars["measurement_step_min"]:
            ax[0] = (old_div(first_I[k][3], first_Z[0][3]))
        if first_I[k][0] == pars["measurement_step_max"]:
            ax[1] = (old_div(first_I[k][3], first_Z[0][3]))
    new_Z, new_I = [], []
    for zrec in first_Z:
        if zrec[0] >= pars['measurement_step_min'] and zrec[0] <= pars['measurement_step_max']:
            new_Z.append(zrec)
    for irec in first_I:
        if irec[0] >= pars['measurement_step_min'] and irec[0] <= pars['measurement_step_max']:
            new_I.append(irec)
    newblock = [new_Z, new_I]
    plot_teq(Figs['eqarea'], newblock, "", pars)
    plt.figure(num=Figs['arai'])
    plt.scatter(ax, ay, marker='d', s=100, c='y')
#
#  find midpoint between two endpoints
#
    sy = []
    sy.append((pars["specimen_b"] * ax[0] +
               old_div(pars["specimen_ytot"], first_Z[0][3])))
    sy.append((pars["specimen_b"] * ax[1] +
               old_div(pars["specimen_ytot"], first_Z[0][3])))
    plt.plot(ax, sy, 'g', linewidth=2)
    bounds = plt.axis()
    if pars['specimen_grade'] != '':
        notestr = 'Grade: ' + pars["specimen_grade"]
        plt.text(.7 * bounds[1], .9 * bounds[3], notestr)
    notestr = 'B: ' + '%6.2f' % (pars["specimen_int"] * 1e6) + ' uT'
    plt.text(.7 * bounds[1], .8 * bounds[3], notestr)