class_docstr: Measures the change in price by calculating the difference between the
  current price and the price from a given period ago
  
  
  Formula:
    - momentum = data - data_period
  
  See:
    - http://en.wikipedia.org/wiki/Momentum_(technical_analysis)
class_docstr_tok: ["Measures","the","change","in","price","by","calculating","the","difference","between","the","current","price","and","the","price","from","a","given","period","ago","Formula",":","-","momentum","=","data","-","data_period","See",":","-","http",":","\/\/en.wikipedia.org\/wiki\/Momentum_","(","technical_analysis",")"]
code: def __init__(self):
      self.l.momentum = self.data - self.data(-self.p.period)
      super(Momentum, self).__init__()
  
file_path: backtrader/backtrader/indicators/momentum.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  from .None import Indicator
label_desc: Use image node_id 1 to create a new Momentum object from inherited base classes: Indicator with example: obj = Momentum()