Sub GAUSSJ(A(), N, B())
Dim IPIV(50), INDXR(50), INDXC(50)
For J = 1 To N
IPIV(J) = 0
Next J
For I = 1 To N
BIG = 0#
For J = 1 To N
If IPIV(J) 1 Then
For K = 1 To N
If IPIV(K) = 0 Then
If Abs(A(J, K)) >= BIG Then
BIG = Abs(A(J, K))
IROW = J
ICOL = K
End If
ElseIf IPIV(K) > 1 Then
Print "Singular matrix"
End If
Next K
End If
Next J
IPIV(ICOL) = IPIV(ICOL) + 1
If IROW ICOL Then
For L = 1 To N
DUM = A(IROW, L)
A(IROW, L) = A(ICOL, L)
A(ICOL, L) = DUM
Next L
DUM = B(IROW)
B(IROW) = B(ICOL)
B(ICOL) = DUM
End If
INDXR(I) = IROW
INDXC(I) = ICOL
If A(ICOL, ICOL) = 0# Then Print "Singular matrix."
PIVINV = 1# / A(ICOL, ICOL)
A(ICOL, ICOL) = 1#
For L = 1 To N
A(ICOL, L) = A(ICOL, L) * PIVINV
Next L
B(ICOL) = B(ICOL) * PIVINV
For LL = 1 To N
If LL ICOL Then
DUM = A(LL, ICOL)
A(LL, ICOL) = 0#
For L = 1 To N
A(LL, L) = A(LL, L) - A(ICOL, L) * DUM
Next L
B(LL) = B(LL) - B(ICOL) * DUM
End If
Next LL
Next I
For L = N To 1 Step -1
If INDXR(L) INDXC(L) Then
For K = 1 To N
DUM = A(K, INDXR(L))
A(K, INDXR(L)) = A(K, INDXC(L))
A(K, INDXC(L)) = DUM
Next K
End If
Next L
End Sub
