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📜  PyBrain-连接

📅  最后修改于: 2020-12-10 05:17:57             🧑  作者: Mango

连接的工作方式类似于图层；唯一的区别是它将数据从网络中的一个节点转移到另一个节点。

在本章中，我们将学习-

  • 了解连接
  • 创建连接

了解连接

这是创建网络时使用的连接的有效示例。

例

ffy.py

from pybrain.structure import FeedForwardNetwork
from pybrain.structure import LinearLayer, SigmoidLayer
from pybrain.structure import FullConnection

network = FeedForwardNetwork()

#creating layer for input => 2 , hidden=> 3 and output=>1
inputLayer = LinearLayer(2)
hiddenLayer = SigmoidLayer(3)
outputLayer = LinearLayer(1)

#adding the layer to feedforward network
network.addInputModule(inputLayer)
network.addModule(hiddenLayer)
network.addOutputModule(outputLayer)

#Create connection between input ,hidden and output
input_to_hidden = FullConnection(inputLayer, hiddenLayer)
hidden_to_output = FullConnection(hiddenLayer, outputLayer)

#add connection to the network
network.addConnection(input_to_hidden)
network.addConnection(hidden_to_output)
network.sortModules()

print(network)

输出

C:\pybrain\pybrain\src>python ffn.py
FeedForwardNetwork-6
Modules:
[, , 
   ]
Connections:
[ 'LinearLayer-8'>, 
    'SigmoidLayer-7'>]

创建连接

在Pybrain中，我们可以使用连接模块创建连接，如下所示-

例

connect.py

from pybrain.structure.connections.connection import Connection
class YourConnection(Connection):
   def __init__(self, *args, **kwargs):
      Connection.__init__(self, *args, **kwargs)
   def _forwardImplementation(self, inbuf, outbuf):
      outbuf += inbuf
   def _backwardImplementation(self, outerr, inerr, inbuf):
      inerr += outer

要创建连接，有2种方法-_forwardImplementation()和_backwardImplementation() 。

调用_forwardImplementation()时，传入模块的输出缓冲区为inbuf ，传出模块的输入缓冲区称为outbuf 。将inbuf添加到传出模块outbuf中。

_backwardImplementation()用externalr ， inerr和inbuf调用。将传出模块错误添加到_backwardImplementation()中的传入模块错误中。

现在让我们在网络中使用YourConnection 。

testconnection.py

from pybrain.structure import FeedForwardNetwork
from pybrain.structure import LinearLayer, SigmoidLayer
from connect import YourConnection

network = FeedForwardNetwork()

#creating layer for input => 2 , hidden=> 3 and output=>1
inputLayer = LinearLayer(2)
hiddenLayer = SigmoidLayer(3)
outputLayer = LinearLayer(1)

#adding the layer to feedforward network
network.addInputModule(inputLayer)
network.addModule(hiddenLayer)
network.addOutputModule(outputLayer)

#Create connection between input ,hidden and output
input_to_hidden = YourConnection(inputLayer, hiddenLayer)
hidden_to_output = YourConnection(hiddenLayer, outputLayer)

#add connection to the network
network.addConnection(input_to_hidden)
network.addConnection(hidden_to_output)
network.sortModules()

print(network)

输出

C:\pybrain\pybrain\src>python testconnection.py
FeedForwardNetwork-6
Modules:
[, , 
   ]
Connections:
[ 'SigmoidLayer-7'>, 
    'LinearLayer-8'>]