code: def plotGenCost(generators):
      
      figure()
      plots = []
      for generator in generators:
          if generator.pcost_model == PW_LINEAR:
              x = [x for x, _ in generator.p_cost]
              y = [y for _, y in generator.p_cost]
          elif generator.pcost_model == POLYNOMIAL:
              x = scipy.arange(generator.p_min, generator.p_max, 5)
              y = scipy.polyval(scipy.array(generator.p_cost), x)
          else:
              raise
          plots.append(plot(x, y))
          xlabel("P (MW)")
          ylabel("Cost ($)")
      legend(plots, [g.name for g in generators])
      show()
docs: Plots the costs of the given generators.