d9r10.frm

数据拟合源程序

VERSION 5.00
Begin VB.Form Form1 
   Caption         =   "Form1"
   ClientHeight    =   4185
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   5385
   LinkTopic       =   "Form1"
   ScaleHeight     =   4185
   ScaleWidth      =   5385
   StartUpPosition =   3  'Windows Default
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   375
      Left            =   3600
      TabIndex        =   0
      Top             =   3480
      Width           =   1335
   End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Private Sub Command1_Click()
    'PROGRAM D9R10
    'Driver for routine MEDFIT
    NPT = 100
    SPREAD = 0.1
    Dim X(100), Y(100), SIG(100)
    IDUM& = -1984
    For I = 1 To NPT
        X(I) = 0.1 * I
        Y(I) = -2# * X(I) + 1# + SPREAD * GASDEV(IDUM&)
        SIG(I) = SPREAD
    Next I
    MWT = 1
    Call FIT(X(), Y(), NPT, SIG(), MWT, A, B, SIGA, SIGB, CHI2, Q)
    Print "According to routine FIT the result is:"
    Print Tab(5)
    Print "A = "; Format$(A, "#.0000"), "Uncertainty: ";
    Print Format$(SIGA, "0.###0")
    Print "B = "; Format$(B, "#.0000"), "Uncertainty: ";
    Print Format$(SIGB, "0.###0")
    Print Tab(5)
    Print "Chi-squared: "; Format$(CHI2, "0.###0"); " for"; NPT; " points"
    Print Tab(5)
    Print "Goodness-of-fit: "; Format$(Q, "0.###0")
    Print Tab(5)
    Print "According to routine MEDFIT the result is:"
    Print Tab(5)
    Call MEDFIT(X(), Y(), NPT, A, B, ABDEV)
    Print "A = "; Format$(A, "0.###0")
    Print "B = "; Format$(B, "0.###0")
    Print Tab(5)
    Print "Absolute deviation (per data point): "; Format$(ABDEV, "0.###0")
    Print Tab(5)
    Print "(note: Gaussian spread is  "; Format$(SPREAD, "0.#0"); ")"
End Sub
   Sub FIT(X(), Y(), NDATA, SIG(), MWT, A, B, SIGA, SIGB, CHI2, Q)
      SX = 0#
      SY = 0#
      ST2 = 0#
      B = 0#
      If MWT <> 0 Then
          SS = 0#
          For I = 1 To NDATA
              WT = 1# / (SIG(I) ^ 2)
              SS = SS + WT
              SX = SX + X(I) * WT
              SY = SY + Y(I) * WT
          Next I
      Else
          For I = 1 To NDATA
              SX = SX + X(I)
              SY = SY + Y(I)
          Next I
          SS = NDATA
      End If
      SXOSS = SX / SS
      If MWT <> 0 Then
          For I = 1 To NDATA
              T = (X(I) - SXOSS) / SIG(I)
              ST2 = ST2 + T * T
              B = B + T * Y(I) / SIG(I)
          Next I
      Else
          For I = 1 To NDATA
              T = X(I) - SXOSS
              ST2 = ST2 + T * T
              B = B + T * Y(I)
      Next I
      End If
      B = B / ST2
      A = (SY - SX * B) / SS
      SIGA = Sqr((1# + SX * SX / (SS * ST2)) / SS)
      SIGB = Sqr(1# / ST2)
      CHI2 = 0#
      If MWT = 0 Then
          For I = 1 To NDATA
              CHI2 = CHI2 + (Y(I) - A - B * X(I)) ^ 2
          Next I
          Q = 1#
          SIGDAT = Sqr(CHI2 / (NDATA - 2))
          SIGA = SIGA * SIGDAT
          SIGB = SIGB * SIGDAT
      Else
          For I = 1 To NDATA
              CHI2 = CHI2 + ((Y(I) - A - B * X(I)) / SIG(I)) ^ 2
          Next I
          Q = GAMMQ(0.5 * (NDATA - 2), 0.5 * CHI2)
      End If
   End Sub
Function GASDEV(IDUM&)
    Static ISET, GSET
    If ISET = 0 Then
      Do
        V1 = 2# * RAN1(IDUM&) - 1#
        V2 = 2# * RAN1(IDUM&) - 1#
        R = V1 ^ 2 + V2 ^ 2
      Loop While R >= 1# Or R = 0
      FAC = Sqr(-2# * Log(R) / R)
      GSET = V1 * FAC
      GASDEV = V2 * FAC
      ISET = 1
    Else
      GASDEV = GSET
      ISET = 0
    End If
End Function
Static Function RAN1(IDUM&)
    Dim R(97)
    M1& = 259200: IA1& = 7141: IC1& = 54773: RM1 = 0.0000038580247
    M2& = 134456: IA2& = 8121: IC2& = 28411: RM2 = 0.0000074373773
    M3& = 243000: IA3& = 4561: IC3& = 51349
    If IDUM& < 0 Or IFF = 0 Then
        IFF = 1
        IX1& = (IC1& - IDUM&) Mod M1&
        IX1& = (IA1& * IX1& + IC1&) Mod M1&
        IX2& = IX1& Mod M2&
        IX1& = (IA1& * IX1& + IC1&) Mod M1&
        IX3& = IX1& Mod M3&
        For J = 1 To 97
            IX1& = (IA1& * IX1& + IC1&) Mod M1&
            IX2& = (IA2& * IX2& + IC2&) Mod M2&
            R(J) = (CSng(IX1&) + CSng(IX2&) * RM2) * RM1
        Next J
        IDUM& = 1
    End If
    IX1& = (IA1& * IX1& + IC1&) Mod M1&
    IX2& = (IA2& * IX2& + IC2&) Mod M2&
    IX3& = (IA3& * IX3& + IC3&) Mod M3&
    J = 1 + Int((97 * IX3&) / M3&)
    If J > 97 Or J < 1 Then Print "Abnormal exit": Exit Function
    RAN1 = R(J)
    R(J) = (CSng(IX1&) + CSng(IX2&) * RM2) * RM1
End Function
  Function GAMMQ(A, X)
      If X < 0# Or A <= 0# Then
         Print "PAUSE"
         Exit Function
      End If
      If X < A + 1# Then
          Call GSER(GAMSER, A, X, GLN)
          GAMMQ = 1# - GAMSER
      Else
          Call GCF(GAMMCF, A, X, GLN)
          GAMMQ = GAMMCF
      End If
   End Function
   Sub GCF(GAMMCF, A, X, GLN)
      ITMAX = 100
      EPS = 0.0000003
      GLN = GAMMLN(A)
      GOLD = 0#
      A0 = 1#
      A1 = X
      B0 = 0#
      B1 = 1#
      FAC = 1#
      For N = 1 To ITMAX
          AN = N

          ANA = AN - A
          A0 = (A1 + A0 * ANA) * FAC
          B0 = (B1 + B0 * ANA) * FAC
          ANF = AN * FAC
          A1 = X * A0 + ANF * A1
          B1 = X * B0 + ANF * B1
          If A1 <> 0# Then
              FAC = 1# / A1
              G = B1 * FAC
              If Abs((G - GOLD) / G) < EPS Then GoTo 1
              GOLD = G
          End If
      Next N
      Print "A too large, ITMAX too small"
1     GAMMCF = Exp(-X + A * Log(X) - GLN) * G
   End Sub
   Sub GSER(GAMSER, A, X, GLN)
      ITMAX = 100
      EPS = 0.0000003
      GLN = GAMMLN(A)
      If X <= 0# Then
          If X < 0# Then
             Print " PAUSE"
             Exit Sub
          End If
          GAMSER = 0#
          Exit Sub
      End If
      AP = A
      Sum = 1# / A
      DEL = Sum
      For N = 1 To ITMAX
          AP = AP + 1#
          DEL = DEL * X / AP
          Sum = Sum + DEL
          If Abs(DEL) < Abs(Sum) * EPS Then GoTo 1
      Next N
      Print "A too large, ITMAX too small"
1     GAMSER = Sum * Exp(-X + A * Log(X) - GLN)
   End Sub
   Function GAMMLN(XX)
      Dim COF(6)
      COF(1) = 76.18009173
      COF(2) = -86.50532033
      COF(3) = 24.01409822
      COF(4) = -1.231739516
      COF(5) = 0.00120858003
      COF(6) = -0.00000536382
      STP = 2.50662827465
      HALF = 0.5
      ONE = 1#
      FPF = 5.5
      X = XX - ONE
      TMP = X + FPF
      TMP = (X + HALF) * Log(TMP) - TMP
      SER = ONE
      For J = 1 To 6
          X = X + ONE
          SER = SER + COF(J) / X
    Next J
      GAMMLN = TMP + Log(STP * SER)
   End Function