Private Sub Command4_Click()
Dim i As Integer
Dim dd As Double
Dim dd2 As Double
Dim dd3 As Double
Dim appoB As Double
Dim appo7 As Double
Dim appo4 As Double
Dim appo2 As Double
Dim appo6 As Double
Dim appo8 As Double
Dim appo9 As Double
Dim StrLog As String

ABORT = False
INIT_TIMER = GetTickCount
CStop.Visible = True

Command4.Enabled = False
Command2.Enabled = False
INDICE_MATRICE1 = TINDICE_MATRICE1
INDICE_MATRICE2 = TINDICE_MATRICE2
ReDim AAA(INDICE_MATRICE2) As Double
ReDim BBB(INDICE_MATRICE2) As Double
ReDim CCC(INDICE_MATRICE2) As Double
ReDim psi(INDICE_MATRICE1, INDICE_MATRICE2) As Double

On Error GoTo yy:

Rho = GiveMeDouble(TRho.Text)
Vfase = GiveMeDouble(TVFase.Text)
V0 = GiveMeDouble(TV0.Text)
deltat = GiveMeDouble(TDeltaT.Text)
nitertemp = GiveMeDouble(Tnitertemp.Text)
N = GiveMeDouble(TN.Text)

A = PIGRECO * GiveMeDouble(TD.Text) * GiveMeDouble(TD.Text) / 4#
TA.Text = Format(A, "0.0000")
p = GiveMeDouble(TP.Text) * 10000
F = p * A
TF.Text = Format(F, "0.0000")

tot = GiveMeDouble(TDeltaT.Text) * GiveMeDouble(Tnitertemp.Text) * GiveMeDouble(TN.Text)
Ttot.Text = tot

B = Vfase * Vfase * Rho
TB.Text = Format(B, "0.0000")

L0 = GiveMeDouble(Tltot.Text) / 10000#
TL0.Text = Format(L0, "0.0000")


LStatus.Caption = "Working..."

Form1.Refresh
For i = 1 To INDICE_MATRICE2

psi(0, i) = L0 + psi(0, i - 1) 'prima colonna nel foglio "A"
AAA(i) = psi(0, i)
Next i
For i = 0 To INDICE_MATRICE2

BBB(i) = AAA(i) - V0 * deltat

Next i
'girotondo 0
If CLogFile.Value Then Open "LogFile.txt" For Output As #1

CCC(0) = 2 * BBB(0) - AAA(0) + 1 / Rho * (deltat / L0) ^ 2 * (p * L0 + B * (BBB(1) - BBB(0) - L0))
For i = 1 To INDICE_MATRICE2 - 1
CCC(i) = 2 * BBB(i) - AAA(i) + B / Rho * (deltat / L0) ^ 2 * (BBB(i + 1) - 2 * BBB(i) + BBB(i - 1))
Next i
CCC(INDICE_MATRICE2) = 2 * BBB(INDICE_MATRICE2) - AAA(INDICE_MATRICE2) + B / Rho * (deltat / L0) ^ 2 * (BBB(INDICE_MATRICE2) - BBB(INDICE_MATRICE2 - 1) - L0)

For J = 1 To nitertemp
'girotondo 1

For K = 0 To N - 2

AAA(0) = 2 * CCC(0) - BBB(0) + 1 / Rho * (deltat / L0) ^ 2 * (p * L0 + B * (CCC(1) - CCC(0) - L0))
For i = 1 To 9998
AAA(i) = 2 * CCC(i) - BBB(i) + B / Rho * (deltat / L0) ^ 2 * (CCC(i + 1) - 2 * CCC(i) + CCC(i - 1))
Next i
AAA(INDICE_MATRICE2) = 2 * CCC(INDICE_MATRICE2) - BBB(INDICE_MATRICE2) + B / Rho * (deltat / L0) ^ 2 * (CCC(INDICE_MATRICE2) - CCC(INDICE_MATRICE2 - 1) - L0)

'girotondo 2

BBB(0) = 2 * AAA(0) - CCC(0) + 1 / Rho * (deltat / L0) ^ 2 * (p * L0 + B * (AAA(1) - AAA(0) - L0))
For i = 1 To INDICE_MATRICE2 - 1
BBB(i) = 2 * AAA(i) - CCC(i) + B / Rho * (deltat / L0) ^ 2 * (AAA(i + 1) - 2 * AAA(i) + AAA(i - 1))
Next i
BBB(INDICE_MATRICE2) = 2 * AAA(INDICE_MATRICE2) - CCC(INDICE_MATRICE2) + B / Rho * (deltat / L0) ^ 2 * (AAA(INDICE_MATRICE2) - AAA(INDICE_MATRICE2 - 1) - L0)
'girotondo extra

CCC(0) = 2 * BBB(0) - AAA(0) + 1 / Rho * (deltat / L0) ^ 2 * (p * L0 + B * (BBB(1) - BBB(0) - L0))
For i = 1 To INDICE_MATRICE2 - 1
CCC(i) = 2 * BBB(i) - AAA(i) + B / Rho * (deltat / L0) ^ 2 * (BBB(i + 1) - 2 * BBB(i) + BBB(i - 1))
Next i
CCC(INDICE_MATRICE2) = 2 * BBB(INDICE_MATRICE2) - AAA(INDICE_MATRICE2) + B / Rho * (deltat / L0) ^ 2 * (BBB(INDICE_MATRICE2) - BBB(INDICE_MATRICE2 - 1) - L0)


Next K

For i = 0 To INDICE_MATRICE2
psi(J, i) = CCC(i)
Next i

  If J = 1 Then N = N + 1
  
   TJ.Text = J
   strfile = J & ") " & psi(J, 0) & " " & Chr(9) & psi(J, INDICE_MATRICE2) & vbCrLf
   If CLogFile.Value Then Print #1, strfile
      
    If J Mod 10 = 0 Then
      Shape2.Width = J / Tnitertemp * 10335
      Shape2.Refresh
      TJ.Refresh
    End If
    If J Mod 10 = 0 Then
     Form1.Refresh
     DoEvents
     If ABORT Then
       CStop.Visible = False
       Command4.Enabled = True
       Command2.Enabled = True
       LStatus.Caption = "Stopped!"
       If CLogFile.Value Then Close #1
       Exit Sub
     End If
    End If


Next J

ok = True
yy:
If Not ok Then
  MsgBox "Error", vbCritical, "Error"
End If
If CLogFile.Value Then Close #1
DammiValoreTimer = (GetTickCount - INIT_TIMER) / 1000#

LStatus.Caption = "Elaboration : " & Format(DammiValoreTimer, "0.000") & " s"
 ' If CFast.Value = 1 Then TLog.Text = StrLog
Command4.Enabled = True
Command2.Enabled = True
CStop.Visible = False
If CLogFileExc.Value Then save_file_excel
End Sub