code: import numpy as np
  import math
  
  _vbars = " ▁▂▃▄▅▆▇█"
  
  def bar_graph(data):
      if len(data) > 64:
          data = np.interp(np.linspace(0, len(data), 64),
                           np.arange(0, len(data)),
                           np.array(data))
  
      M = max(data)
      def _bar(alpha):
          if math.isnan(alpha):
              return 'N'
          else:
              n = int((len(_vbars) - 1) * max(0.0, min(1.0, alpha)))
              return _vbars[n]
  
      if M > 0:
          return ''.join([_bar(x/M) for x in data])
      else:
          return len(data) * ' '
  
apis: numpy.array