VB求同一纬度线上的两城市地表距离用反三角函数做

Question

VB求同一纬度线上的两城市地表距离用反三角函数做

Answer 1

Function ArcSin(X) As Double '反正弦
ArcSin = Atn(X / Sqr(-X * X + 1))
End Function
Private Sub Command1_Click()
a = Val(Text2.Text) ’a地经度
b = Val(Text3.Text) ‘b地经度
c = Abs(a - b)
d = Val(Text1.Text) ‘纬度
If c > 180 Then c = 360 - c
r = 6378.137 * Cos(d * 3.1415926535897 / 180)
l = r * Sin(3.1415926535897 * c / 360)
X = 2 * ArcSin(l / 6378.137) * 6378.137
Text4.Text = X
End Sub