code: def acorr_plot(acorr, linewidth=8, xlabel=None, ax=None):
      import matplotlib.pyplot as plt
  
      if ax is None:
          ax = plt.gca()
  
      if xlabel is None:
          xlabel = np.arange(len(acorr))
  
      ax.vlines(xlabel, [0], acorr, lw=linewidth)
  
      ax.axhline(0, color="k")
      ax.set_ylim([-1, 1])
  
      # hack?
      ax.set_xlim([-1, xlabel[-1] + 1])
  
file_path: statsmodels/statsmodels/tsa/vector_ar/plotting.py
imports: from statsmodels.compat.python import lrange
  import numpy
  import statsmodels.tsa.vector_ar.util
label_desc: Use image node_id 5 for calling a global function with example usage: acorr_plot(acorr, linewidth, xlabel, ax) without return types