重心法选址.doc

2单设施重心法选址2.1实验目的掌握单设施重心法选址的原理，能够计算简单选址题目中待选设施的位置；掌握单设施重心选址的算法流程，能够设计类似题目的算法流程，并编写程序。2.2实验过程(1)单设施重心法选址的原理重心法选址模型示意图如图2-1所示。图2-1 单设施重心法选址选址示意图求解目标：C-总成本最低 其中：fi-序号为i的点的运输费率； Vi-序号为i的点的产量或者销量； di-序号为i的点到待选设施点的相对距离。待选设施位置的计算公式：其中：Xc-重心的X坐标； Yc-重心的Y坐标； Xi-第i个地点X坐标； Yi-第i个地点Y坐标； (2)算法流程图，如图2-2所示。图2-2 算法流程图2.3实验结果（1）单设施重心法选址程序参数设定及其求解界面如图2-3所示。图2-3 单设施重心法选址程序参数设定及其求解界面（2）参数设定及其求解界面变量声明部分（代码）Private Sub Command1_Click() If Text1.Text = Then MsgBox X-横坐标不允许为空 Text1.SetFocus Exit Sub ElseIf IsNumeric(Text1.Text) = False Then MsgBox X-横坐标必须为数值型数据！ Text1.Text = Text1.SetFocus Exit Sub End If If Text2.Text = Then MsgBox Y-纵坐标不允许为空 Text2.SetFocus Exit Sub ElseIf IsNumeric(Text2.Text) = False Then MsgBox Y-纵坐标必须为数值型数据！ Text2.Text = Text2.SetFocus Exit Sub End If If Text3.Text = Then MsgBox 产量或销量不允许为空 Text3.SetFocus Exit Sub ElseIf IsNumeric(Text3.Text) = False Then MsgBox 产量或销量应为数值型数据！ Text3.Text = Text3.SetFocus Exit Sub ElseIf Val(Text3.Text) 0 Then MsgBox 产量或销量应为正数，否则无实际意义！ Text3.Text = Text3.SetFocus Exit Sub End If If Text4.Text = Then MsgBox 运输费率不允许为空 Text4.SetFocus Exit Sub ElseIf IsNumeric(Text4.Text) = False Then MsgBox 运输费率应为数值型数据！ Text4.Text = Text4.SetFocus Exit Sub ElseIf Val(Text4.Text) 0 Then MsgBox 运输费率应为正数，否则无实际意义！ Text4.Text = Text4.SetFocus Exit Sub End If If Text5.Text = Then MsgBox X0-横坐标不允许为空 Text5.SetFocus Exit Sub ElseIf IsNumeric(Text5.Text) = False Then MsgBox X0-横坐标必须为数值型数据！ Text5.Text = Text5.SetFocus Exit Sub End If If Text6.Text = Then MsgBox Y0-纵坐标不允许为空 Text6.SetFocus Exit Sub ElseIf IsNumeric(Text6.Text) = False Then MsgBox Y0-纵坐标必须为数值型数据！ Text6.Text = Text6.SetFocus Exit Sub End If If Text7.Text = Then MsgBox 精度不允许为空 Text7.SetFocus Exit Sub ElseIf IsNumeric(Text7.Text) = False Then MsgBox 精度应为数值型数据！ Text7.Text = Text7.SetFocus Exit Sub ElseIf Val(Text7.Text) = 2 Then Command2.Enabled = True End IfEnd SubPrivate Sub Command2_Click() Xc = Val(Text5.Text) Yc = Val(Text6.Text) JD = Val(Text7.Text) Dim SumCO As Double Dim SumCN As Double Dim Sum1 As Double Dim Sum2 As Double Dim Sum3 As Double For j = 1 To 10000 SumCO = 0 SumCN = 0 Sum1 = 0 Sum2 = 0 Sum3 = 0 For i = 1 To List1.ListCount di = Sqr(Xc - Val(List1.List(i - 1) 2 + (Yc - Val(List2.List(i - 1) 2) 距离公式 SumCO = SumCO + Val(List3.List(i - 1) * Val(List4.List(i - 1) * di Sum1 = Sum1 + (Val(List1.List(i - 1) * Val(List3.List(i - 1) * Val(List4.List(i - 1) / di Sum2 = Sum2 + (Val(List2.List(i - 1) * Val(List3.List(i - 1) * Val(List4.List(i - 1) / di Sum3 = Sum3 + (Val(List3.List(i - 1) * Val(List4.List(i - 1) / di Next i Xc = Sum1 / Sum3 Yc = Sum2 / Sum3 For i = 1 To List1.ListCount di = Sqr(Xc - Val(List1.List(i - 1) 2 + (Yc - Val(List2.List(i - 1) 2) SumCN = SumCN + Val(List3.List(i - 1) * Val(List4.List(i - 1) * di Next i If (SumCO - SumCN) = JD Then Text8.Text = Xc Text9.Text = Yc Text10.Text = SumCN Text11.Text = j Exit For End If Next jEnd SubPrivate Sub List1_Click() For i = 1 To List1.ListCount If List1.Selected(i - 1) = True Then h = InputBox(请输入要改的参数：, 参数修正) If h And IsNumeric(h) = True Then List1.List(i - 1) = h Else: MsgBox 输入的数据必须为数值型数据 End If End If Next iEnd SubPrivate Sub List2_Click() For i = 1 To List2.ListCount If List2.Selected(i - 1) = True Then h = InputBox(请输入要改的参数：, 参数修正) If h And IsNumeric(h) = True Then List2.List(i - 1) = h Else: MsgBox 输入的数据必须为数值型数据 End If End If Next iEnd SubPrivate Sub List3_Click() For i = 1 To List3.ListCount If List3.Selected(i - 1) = True Then h = InputBox(请输入要改的参数：, 参数修正) If h And IsNumeric(h) = True And Val(h) 0 Then List3.List(i - 1) = h Else: MsgBox 输入的数据必须为数值型数据 End If End If Next iEnd SubPrivate Sub List4_Click() For i = 1 To List4.ListCount If List4.Selected(i - 1) = True Then h = I