Rank の計算

gistfile1.vb

Public Function rank (m As ULong(,)) As Integer
    ' m は size * size 行列
    Dim mi As Integer = size - 1
    For i As Integer = 0 To size - 1
        Dim pj As Integer
        pj = -1
        While pj < 0
            For j As Integer = 0 To size - 1
                If m(i, j) Then
                    pj = j
                    Exit While
                End If
            Next
            If pj < 0 Then
                If mi <= i Then Return i
                For j As Integer = 0 To size - 1
                    m(i, j) = m(mi, j)
                    m(mi, j) = 0
                Next
                mi -= 1
            End If
        End While
        Dim f = inverse(m(i, pj))
        For j As Integer = 0 To size - 1
            If j = pj Then Continue For
            For ii As Integer = i + 1 To size - 1
                Dim d = (f * m(ii, pj) Mod Ch) * m(i, j) Mod Ch
                If m(ii, j) < d Then
                    m(ii, j) += (Ch - d)
                Else
                    m(ii, j) -= d
                End If
                ' m(ii, j) -= f * m(ii, pj) * m(i, j)
            Next
        Next
        For ii As Integer = i + 1 To size - 1
            m(ii, pj) = 0
        Next
    Next
    Return size
End Function