def _fit_wide_matrix(matrix, syn_obj, max_cols):
    """
    make the wide matrix narrower by substituting horizontal ... in the rows
    """
    mat = matrix[:, :max_cols - 2].tolist()
    last_col = matrix[:, (-1)].tolist()
    for index, element in enumerate(mat):
        element += [syn_obj.cdots, last_col[index][0]]
    return mat
