docs: def plot_hpars(HDD, hpars, sym):
      """
      function to plot hysteresis parameters
      deprecated (used in hysteresis_magic)
      """
      plt.figure(num=HDD['hyst'])
      X, Y = [], []
      X.append(0)
      Y.append(old_div(float(hpars['hysteresis_mr_moment']), float(
          hpars['hysteresis_ms_moment'])))
      X.append(float(hpars['hysteresis_bc']))
      Y.append(0)
      plt.plot(X, Y, sym)
      bounds = plt.axis()
      n4 = 'Ms: ' + '%8.2e' % (float(hpars['hysteresis_ms_moment'])) + ' Am^2'
      plt.text(bounds[1] - .9 * bounds[1], -.9, n4)
      n1 = 'Mr: ' + '%8.2e' % (float(hpars['hysteresis_mr_moment'])) + ' Am^2'
      plt.text(bounds[1] - .9 * bounds[1], -.7, n1)
      n2 = 'Bc: ' + '%8.2e' % (float(hpars['hysteresis_bc'])) + ' T'
      plt.text(bounds[1] - .9 * bounds[1], -.5, n2)
      if 'hysteresis_xhf' in list(hpars.keys()):
          n3 = r'Xhf: ' + '%8.2e' % (float(hpars['hysteresis_xhf'])) + ' m^3'
          plt.text(bounds[1] - .9 * bounds[1], -.3, n3)
      plt.figure(num=HDD['deltaM'])
      X, Y, Bcr = [], [], ""
      if 'hysteresis_bcr' in list(hpars.keys()):
          X.append(float(hpars['hysteresis_bcr']))
          Y.append(0)
          Bcr = float(hpars['hysteresis_bcr'])
      plt.plot(X, Y, sym)
      bounds = plt.axis()
      if Bcr != "":
          n1 = 'Bcr: ' + '%8.2e' % (Bcr) + ' T'
          plt.text(bounds[1] - .5 * bounds[1], .9 * bounds[3], n1)