Spilu problem demonstration

spilu_demo.py

#!/usr/bin/env python3

from scipy.sparse.linalg import spilu
from scipy.sparse import identity

matrix = identity(2)
options = {'spilu_drop_tol':1e-4,
            'spilu_fill_factor':10,
            'spilu_drop_rule':'basic,area',
            'spilu_permc_spec':'COLAMD'
        }
try:
    ilu = spilu(matrix, drop_tol=options['spilu_drop_tol'], fill_factor=options['spilu_fill_factor'],
        drop_rule=options['spilu_drop_rule'], permc_spec=options['spilu_permc_spec'])
except TypeError as tp:
    assert "a bytes-like object is required, not 'str'" in str(tp)
    print('Variant 1 failed')

try:
    ilu = spilu(matrix, drop_tol=options['spilu_drop_tol'], fill_factor=options['spilu_fill_factor'],
        drop_rule=options['spilu_drop_rule'].encode('UTF-8'), permc_spec=options['spilu_permc_spec'].encode('UTF-8'))
except TypeError as tp:
    assert "a bytes-like object is required, not 'str'" in str(tp)
    print('Variant 2 failed')

print('Variant 3 ok')
ilu = spilu(matrix, drop_tol=options['spilu_drop_tol'], fill_factor=options['spilu_fill_factor'],
        permc_spec=options['spilu_permc_spec'].encode('UTF-8'))

print('Variant 4 ok')
ilu = spilu(matrix, drop_tol=options['spilu_drop_tol'], fill_factor=options['spilu_fill_factor'],
        permc_spec=options['spilu_permc_spec'])