Private Sub Form_Load()

'定义神经网络的参数
Dim InputNodes = 3 '输入层节点数量 
Dim HiddenNodes = 4 '隐藏层节点数量 
Dim OutputNodes = 2 '输出层节点数量

'初始化权重，从-1到1之间随机取值 
Randomize 
 Dim InputWeights(InputNodes, HiddenNodes) As Double  

 For i As Integer = 0 To InputNodes - 1  
    For j As Integer = 0 To HiddenNodes - 1  
        InputWeights(i, j) = (Rnd * 2) - 1  
    Next  
 Next  

 Dim OutputWeights(HiddenNodes, OutputNodes) As Double  

 For i As Integer = 0 To HiddenNodes - 1  
    For j As Integer = 0 To OutputNodes - 1  
        OutputWeights(i, j) = (Rnd * 2) - 1  
    Next  
 Next

'定义激活函数（Sigmoid函数） 

 Function Sigmoid(ByVal x As Double) As Double  Return (1 / (1 + Exp(-x))) End Function 

  '定义前向传播函数，用于将神经元的信号向前传递并得到最后的预测值。 

  Sub ForwardPropagate(ByVal inputs() As Double, ByVal output()As Double )Dim hiddenLayerOutputs(Hidden N odes-1 )AsDoubleForiAsInteger=0ToHidden N odes-1DimsumAsDouble=0ForjAsInteger=0ToInput N odes-1sum+=inputs(j)*Input Weights (j , i )Nexthidden LayerOutputs (i)=Sigmoid (sum )NextDimoutputLayerOutputs (Output N odes-1 )AsDoubleForiAsInteger=0ToOutput N odes-1Dim sumA sDoub le=0F orjA sI nteger=0T oHidde nNode s- 1sum+=hidden LayerO utputs (j)*Outpu t Weigh ts (j , i )Ne xte routput LayerO utput s(i)=Sigmo id(su m)Ne xte rout put=ou tput Laye rOutp u tsEndSubEndSub