-(xx)/2
做了一个公式f(y)=(y-5)∫(-∞)e d(x)
y-5 和 -∞在∫上下 -(xx)/2是 e 的密数
代码为
Public Function f(ByVal X!) '被积函数
f = Exp((-0.5 * X ^ 2))
End Function
Public Function trapez(ByVal a!, ByVal b!, ByVal n&) As Single
'b、a分别为积分上下限,n为等分数
Dim sum!, h!, X!, i&
h = (b - a) / n
sum = (f(a) + f(b)) / 2
For i = 1 To n - 1
X = a + i * h
sum = sum + f(X)
Next i
trapez = sum * h
End Function
那为朋友能帮我看下, 万分感谢
做了一个公式f(y)=(y-5)∫(-∞)e d(x)
y-5 和 -∞在∫上下 -(xx)/2是 e 的密数
代码为
Public Function f(ByVal X!) '被积函数
f = Exp((-0.5 * X ^ 2))
End Function
Public Function trapez(ByVal a!, ByVal b!, ByVal n&) As Single
'b、a分别为积分上下限,n为等分数
Dim sum!, h!, X!, i&
h = (b - a) / n
sum = (f(a) + f(b)) / 2
For i = 1 To n - 1
X = a + i * h
sum = sum + f(X)
Next i
trapez = sum * h
End Function
那为朋友能帮我看下, 万分感谢
最好 代码
'b、a分别为积分上下限,n为等分数
Dim sum!, h!, X!, i&,f1!,f2!
h = (b - a) / n
f1=f(a)
sum=0
For i = 1 To n
X = a + i * h
f2=f(X)
sum = sum + (f1+f2)/2*h
f1=f2
Next i
trapez = sum
End Function