VBA Matrix Operations Help Needed.

[dennygibson]

How are A2, B2, C2, defined, and what are their values?

I knew someone would ask … I didn't include them because the whole code is fairly long (and getting longer). Here's the hole thing so far:

Option Explicit
Option Base 1
Sub Coefficients()
Dim ShMain As Worksheet
Dim Rswrl As Variant
Dim Lswrl As Variant
Dim Ror As Variant
Dim Alpha As Variant
Dim rho_liq As Variant
Dim visc As Variant
Dim rho_air As Variant
Dim surfT_liquid As Variant
Dim Omega As Variant
Dim Re As Variant
Dim Ain As Variant
Dim V1 As Variant
Dim Ri As Variant
Dim R As Variant
Dim psi As Variant
Dim psipsi As Variant
Dim a As Variant
Dim b As Variant
Dim h As Variant
Dim sum As Variant
Dim First As Variant
Dim Last As Variant
Dim A1 As Variant
Dim A2 As Variant
Dim B1 As Variant
Dim B2 As Variant
Dim C2 As Variant
Dim A3 As Variant
Dim B3 As Variant
Dim B33 As Variant
Dim C3 As Variant
Dim B4 As Variant
Dim A4 As Variant
Dim W1 As Variant
Dim Del1 As Variant
Dim C As Variant
Dim D As Variant
Dim F As Variant
Dim Pi As Variant
ReDim C(1 To 2, 1 To 2)
ReDim D(1 To 2, 1 To 1)
ReDim F(1 To 2, 1 To 1)
ReDim Cinv(1 To 2, 1 To 2)
Dim npts As Long
Dim k As Long
' Input Values:
' Geometry:
    Rswrl = ActiveSheet.Range("H18").Value / 2
    Lswrl = ActiveSheet.Range("H14").Value
    Ror = ActiveSheet.Range("H20").Value / 2
    Alpha = ActiveSheet.Range("H21").Value
    Ri = ActiveSheet.Range("H17").Value
' Properties:
    rho_liq = ActiveSheet.Range("H8").Value
    visc = ActiveSheet.Range("H9").Value
    rho_air = ActiveSheet.Range("H10").Value
    surfT_liquid = ActiveSheet.Range("H11").Value
' Preliminaries
    Pi = 3.14159265
    Ain = ActiveSheet.Range("H23").Value
    V1 = ActiveSheet.Range("H24").Value
' Swirl Chamber
    Omega = V1 * (Rswrl - Ri)
    Re = Omega / visc
    R = Rswrl
'   Coefficients (constants - variable values must be added.
'    Coefficient A1
        npts = 100
        b = 1#
        a = 0#
        h = (b - a) / npts
    
'    First and Last Integration Points
        First = (2 * a - a ^ 2) - (2 * a - a ^ 2) ^ 2
        Last = (2 * b - b ^ 2) - (2 * b - b ^ 2) ^ 2
        sum = First
'    Odd terms
        For k = 1 To npts - 1 Step 2
            psi = 2 * k * h - (k * h) * (k * h)
            sum = sum + 4 * (psi - psi * psi)
        Next k
'    Even terms
        For k = 2 To npts - 1 Step 2
            psi = 2 * k * h - (k * h) * (k * h)
            sum = sum + 2 * (psi - psi * psi)
        Next k
 '   Add final value
        sum = sum + Last
        A1 = h / 3 * sum
        ActiveSheet.Range("R5") = A1
    
'    Coefficient A2
        npts = 50
        b = 1#
        a = 0#
        h = (b - a) / npts
'    First and Last Integration Points
        First = (2 * a - a ^ 2)
        Last = (2 * b - b ^ 2)
        sum = First
'    Odd terms
        For k = 1 To npts - 1 Step 2
            psi = 2 * k * h - (k * h) * (k * h)
            sum = sum + 4 * psi
        Next k
'    Even terms
        For k = 2 To npts - 1 Step 2
            psi = 2 * k * h - (k * h) * (k * h)
            sum = sum + 2 * psi
        Next k
 '   Add final value
        sum = sum + Last
        A2 = h / 3 * sum
        ActiveSheet.Range("R6") = A2
 
 '   Coefficient B1 and C2
        b = 1#
        a = 0#
        B1 = (2 - 2 * b) - (2 - 2 * a)
        ActiveSheet.Range("R7") = B1
        C2 = B1
        ActiveSheet.Range("R9") = C2
 
 '   Coefficient B2
        npts = 100
        b = 1#
        a = 0#
        h = (b - a) / npts
'    First and Last Integration Points
        First = (2 * a - a ^ 2) ^ 2
        Last = (2 * b - b ^ 2) ^ 2
        sum = First
'    Odd terms
        For k = 1 To npts - 1 Step 2
            psipsi = (2 * k * h - (k * h) * (k * h)) * (2 * k * h - (k * h) * (k * h))
            sum = sum + 4 * psipsi
        Next k
'    Even terms
        For k = 2 To npts - 1 Step 2
            psipsi = (2 * k * h - (k * h) * (k * h)) * (2 * k * h - (k * h) * (k * h))
            sum = sum + 2 * psipsi
        Next k
 '   Add final value
        sum = sum + Last
        B2 = h / 3 * sum
        ActiveSheet.Range("R8") = B2
'Set initial conditions
        W1 = 0
        Del1 = 0.05
'    Swirl Chamber Coefficient Assembly
        C(1, 1) = Del1 * W1
        C(1, 2) = Del1 ^ 2
        C(2, 1) = ((A2 - B2) * Del1 * W1 ^ 2)
        C(2, 2) = ((A2 - 2 * B2 + 1) * Del1 ^ 2 * W1)
        D(1, 1) = B1 / A1
        D(2, 1) = C2 * W1
        ActiveSheet.Range("T5") = C(1, 1)
        ActiveSheet.Range("U5") = C(1, 2)
        ActiveSheet.Range("T6") = C(2, 1)
        ActiveSheet.Range("U6") = C(2, 2)
        ActiveSheet.Range("X5") = D(1, 1)
        ActiveSheet.Range("X6") = D(2, 1)
'    Get F
        F = WorksheetFunction.MMult(WorksheetFunction.MInverse(C), D)
        
        
' Spin Chamber
'    Coefficients
        A3 = A1
        B3 = A2
        B33 = B2
        C3 = B1
        B4 = C2
        A4 = A1
        ActiveSheet.Range("R10") = A3
        ActiveSheet.Range("R11") = B3
        ActiveSheet.Range("R12") = B33
        ActiveSheet.Range("R13") = C3
        ActiveSheet.Range("R14") = B4
        ActiveSheet.Range("R15") = A4

' Spray Orifice
        Omega = ActiveSheet.Range("H25")
        Re = ActiveSheet.Range("H26")
        R = Ror
    
' Solve Momentum Equations

        
' Zone 1
        
End Sub