Laboratoire de l'Informatique et du Parallélisme » Pobyso

def smo_is_upper_triangular_matrix(mat):

    """

    Check that the matrix is upper triangular.

    """

    dimensions = mat.dimensions()

    # Must be a bidimensional matrix.

    if len(dimensions) != 2:

        return False

    # Must be square.

    if dimensions[0] != dimensions[1]:

        return False

    # A 1x1 matrix is lower triangular.

    if dimensions[0] == 1:

        return True

    for rowIndex in xrange(1, dimensions[0]):

        for colIndex in xrange(0, rowIndex):

            if mat[rowIndex, colIndex] != 0:

                print mat.rows()[rowIndex]

                return False

    return True

# End smo_is_upper_triangular_matrix

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