这是我第一次编码,所以我有一些简单的查询。所以我在 hopfield 网络中遇到了这个问题,我试图在代码末尾的 4 种模式上“训练”我的网络。然后我需要运行 10 次迭代来看看会发生什么。
但是当我尝试运行它时,我得到的输出值都与初始值相同。所以我不确定我做错了什么。或者这是否意味着网络已进入稳定状态?
#
# Preparations
#
nodes=[]
NUMNODES=16
training=[]
#
# Defining Node Class
#
class Node(object):
def __init__(self,name=None):
self.name=name
self.activation_threshold=0.0
self.net_input=0.0
self.outgoing_connections=[]
self.incoming_connections=[]
self.connections=[]
self.activation=None
def __str__(self):
return self.name
def addconnection(self,sender,weight=1.0):
self.connections.append(Connection(self,sender,weight))
def update_input(self):
self.net_input=0.0
for conn in self.connections:
self.net_input = (conn.weight * conn.sender.activation)
print 'Updated Input for node', str(self), 'is', self.net_input
def update_activation(self):
if self.net_input > self.activation_threshold:
self.activation = 1.0
elif self.net_input <= self.activation_threshold:
self.activation = 0.0
print 'Updated Activation for node', str(self), 'is', self.activation
def update_training(self):
Node = random.choice(nodes)
#
# Defining Connection Class
#
class Connection(object):
def __init__(self, sender, reciever, weight):
self.weight=weight
self.sender=sender
self.reciever=reciever
sender.outgoing_connections.append(self)
reciever.incoming_connections.append(self)
#
# Other Programs
#
def set_activations(act_vector):
"""Activation vector must be same length as nodes list"""
for i in xrange(len(act_vector)):
nodes[i].activation = act_vector[i]
for i in xrange(NUMNODES):
nodes.append(Node(str(i)))
for i in xrange(NUMNODES):#go thru all the nodes calling them i
for j in xrange(NUMNODES):#go thru all the nodes calling them j
if i!=j:#as long as i and j are not the same
nodes[i].addconnection(nodes[j])#connects the nodes together
#
# Training Pattern
#
set_activations([1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0])
set_activations([1.0,1.0,1.0,1.0,0.0,0.0,0.0,0.0,1.0,1.0,1.0,1.0,1.0,0.0,0.0,0.0])
set_activations([1.0,1.0,0.0,0.0,1.0,1.0,0.0,0.0,1.0,1.0,0.0,0.0,1.0,1.0,0.0,0.0])
set_activations([1.0,0.0,1.0,0.0,1.0,0.0,1.0,0.0,1.0,0.0,1.0,0.0,1.0,0.0,1.0,0.0])
#
# Running 10 Iterations
#
for i in xrange(10):
print ' *********** Iteration', str(i+1), '***********'
for thing in nodes:
thing.update_training()
thing.update_input()
thing.update_activation()