'---------------------------我自己写的积分函数(抛物线求积分法)
'AA--积分下限,BB--积分上限,N--分段数
Function integralX(AA As Double, BB As Double, N As Integer)
Dim dblTemp1 As Double
Dim dblTemp2 As Double
Dim dblTemp3 As Double
Dim dblTemp4 As Double
Dim i As Integer
Dim Sum As Double
dblTemp1 = (BB - AA) / N
dblTemp2 = FUNC(AA) + FUNC(BB) '**
dblTemp3 = 0#
For i = 2 To N - 2 Step 2
dblTemp3 = dblTemp3 + (2 * FUNC(AA + (dblTemp1 * i))) '**
Next i
dblTemp4 = 0#
For i = 1 To N - 1 Step 2
dblTemp4 = dblTemp4 + (4 * FUNC(AA + (dblTemp1 * i)))
Next i
Sum = (1 / 3) * dblTemp1 * (dblTemp2 + dblTemp3 + dblTemp4)
integralX = Sum
End Function
'AA--积分下限,BB--积分上限,N--分段数
Function integralX(AA As Double, BB As Double, N As Integer)
Dim dblTemp1 As Double
Dim dblTemp2 As Double
Dim dblTemp3 As Double
Dim dblTemp4 As Double
Dim i As Integer
Dim Sum As Double
dblTemp1 = (BB - AA) / N
dblTemp2 = FUNC(AA) + FUNC(BB) '**
dblTemp3 = 0#
For i = 2 To N - 2 Step 2
dblTemp3 = dblTemp3 + (2 * FUNC(AA + (dblTemp1 * i))) '**
Next i
dblTemp4 = 0#
For i = 1 To N - 1 Step 2
dblTemp4 = dblTemp4 + (4 * FUNC(AA + (dblTemp1 * i)))
Next i
Sum = (1 / 3) * dblTemp1 * (dblTemp2 + dblTemp3 + dblTemp4)
integralX = Sum
End Function
解决方案 »
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