code: def mean_absolute_error(y_true, y_pred):
      result = mean(abs(y_true - y_pred), axis=1)
      return result
  
imports: from zoo.common.nncontext import *
  from zoo.pipeline.api.autograd import *
  from zoo.pipeline.api.keras.layers import *
  from zoo.pipeline.api.keras.models import *
  from optparse import OptionParser
label_desc: Use image node_id 1 for calling a global function with example usage: mean_absolute_error(y_true, y_pred) and returns: result