code: def _get_irf_plot_config(names, impcol, rescol):
      nrows = ncols = k = len(names)
      if impcol is not None and rescol is not None:
          # plot one impulse-response pair
          nrows = ncols = 1
          j = util.get_index(names, impcol)
          i = util.get_index(names, rescol)
          to_plot = [(j, i, 0, 0)]
      elif impcol is not None:
          # plot impacts of impulse in one variable
          ncols = 1
          j = util.get_index(names, impcol)
          to_plot = [(j, i, i, 0) for i in range(k)]
      elif rescol is not None:
          # plot only things having impact on particular variable
          ncols = 1
          i = util.get_index(names, rescol)
          to_plot = [(j, i, j, 0) for j in range(k)]
      else:
          # plot everything
          to_plot = [(j, i, i, j) for i in range(k) for j in range(k)]
  
      return nrows, ncols, to_plot
  
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 9 for calling a global function with example usage: _get_irf_plot_config(names, impcol, rescol) and returns: nrows,  ncols,  to_plot