old_contents: import paddle.v2 as paddle
  import numpy as np
  
  paddle.init(use_gpu=False)
  x = paddle.layer.data(name='x', type=paddle.data_type.dense_vector(2))
  y_predict = paddle.layer.fc(input=x, size=1, act=paddle.activation.Linear())
  
  # loading the model which generated by training
  with open('hello_params_pass_90.tar', 'r') as f:
      parameters = paddle.parameters.Parameters.from_tar(f)
  
  i = [[[1, 2]]]
  
  print paddle.infer(output_layer=y_predict, parameters=parameters, input=i)
  
new_contents: import paddle.v2 as paddle
  import numpy as np
  
  paddle.init(use_gpu=False)
  x = paddle.layer.data(name='x', type=paddle.data_type.dense_vector(2))
  y_predict = paddle.layer.fc(input=x, size=1, act=paddle.activation.Linear())
  
  # loading the model which generated by training
  with open('params_pass_90.tar', 'r') as f:
      parameters = paddle.parameters.Parameters.from_tar(f)
  
  # Input multiple sets of data，Output the infer result in a array.
  i = [[[1, 2]], [[3, 4]], [[5, 6]]]
  print paddle.infer(output_layer=y_predict, parameters=parameters, input=i)
  # Will print:
  # [[ -3.24491572]
  #  [ -6.94668722]
  #  [-10.64845848]]
  
subject: Update infer.py