For without next error.

[quayz15]

I am trying to teach myself VB and this is my first real program. So, I'm sure this is a simple question. I'm trying to write a program that will process the information given by the manufacturer in a spread sheet, and predict the result. I'm sure that at this point there are many errors in the program but I cant get passed the For without Next error that pops up. I don't understand this because my for loop does have a next statment in it. I'm tring to train myself to think like a programmer so a detailed explanation is appreciated.
Here is what I have so far.

Option Explicit

Private Sub Command1_Click()


Dim x As Range
Dim time As Range
Dim xdot As Range
Dim s As Integer
Dim xddot As Range
Dim timestep As Integer
s = InputBox("Enter Time Steps.")

For timestep = 1 To s
timestep = 1
time = Range("A14").End(xlDown).Offset(1, 0).Select
x = Range("B14").End(xlDown).Offset(1, 0).Select
xdot = Range("C14").End(xlDown).Offset(1, 0).Select
xddot = (xdot - xdot(-1, 0)) / (time - time(-1, 0))
Range("D14").Value = xddot

Dim k1, k2, k3, k4 As Double
Dim z, h As Double
Dim i As Long
z = 1
h = xddot - xddot(-1, 0)

k1 = h * f(xdot, z)
k2 = h * f(xdot + h / 2, z + k1 / 2)
k3 = h * f(xdot + h / 2, z + k2 / 2)
k4 = h * f(xdot + h, z + k3)
z = z + k1 / 6 + k2 / 3 + k3 / 3 + k4 / 6

xdot = xdot + h

Print "when xdot = "; xdot; "z = "; z

End Sub
Function f(xddot, z) As Double
Dim A As Range
Dim n As Range
Dim gamma As Range
Dim betta As Range

If z > 0 And xddot > 0 Then
f = A - (z ^ n) * (gamma + betta)
End If
If z > 0 And xddot < 0 Then
f = A + (z ^ n) * (gamma - betta)
End If
If z < 0 And xddot < 0 Then
f = A - Abs(z ^ n) * (gamma + betta)
End If
If z < 0 And xddot > 0 Then
f = A + Abs(z ^ n) * (gamma - betta)
End If
End Function


Function c(xdot) As Double
Dim a1 As Range
Dim a2 As Range
Dim p As Range
c = a1 * e ^ (-(a2 * Abs(xdot)) ^ p)

End Function

Function fc() As Double
Dim alfa As Range
Dim k As Range
Dim m As Range
fc = alfa * z + k * x + c(xdot) * xdot + m * xddot

End Function
Dim f0 As Double
Dim ft As Double
ft = fc - f0

Cells(timestep + 13, 5) = ft
Next timestep
End Sub

I tried to remove the first End sub but I get an expected end sub error

 

[gmmastros]

The problem is that you cannot have functions embedded within a function. (this also applies to subroutines).

to cut down the code (for clarification purposes)...

Private Sub Command1_Click()

Dim ....

[!]For timestep = 1 To s[/!]
  Statements....
End Sub

Function f(xddot, z) As Double
End Function

Function c(xdot) As Double
End Function

Function fc() As Double
End Function

[!]Next timestep[/!]
End Sub

Every For must have a next, but you cannot define functions within the for next loop. You can call functions, but not declare them. Like this....

Private Sub Command1_Click()

Dim ....

[!]For timestep = 1 To s[/!]
  Statements....
  Use your functions here.
  X = f(Blah)
  y = c(Floo)
  
[!]Next timestep[/!]
End Sub

Function f(xddot, z) As Double
End Function

Function c(xdot) As Double
End Function

Function fc() As Double
End Function

-George

"The great things about standards is that there are so many to choose from." - Fortune Cookie Wisdom

 

[Andrzejek]

Also, from your code:
[tt]
s = InputBox("Enter Time Steps.")

For timestep = 1 To s[blue]
timestep = 1[/blue]
....[/tt]

Your variable timestep will always be reset to 1 in your For ... Next loop

Eliminate BLUE code

Have fun.

---- Andy