1 | initial version |
Hello,
Indeed there is a bug
sage: u = C((0, 0, 0, 0, 0, 0, 0))
sage: v = C((1, 0, 0, a + 1, 0, 1, 0))
sage: u in C and v in C
True
And the hamming weight of v = v-u is 3... Actually there are two algorithms in Sage and both of them fail
sage: LinearCode(G).minimum_distance(algorithm="guava")
5
sage: LinearCode(G).minimum_distance(algorithm="gap")
5
One possible reason is that it is not over a prime field.
Vincent
2 | No.2 Revision |
Hello,
Indeed there is a bug
sage: u = C((0, 0, 0, 0, 0, 0, 0))
sage: v = C((1, 0, 0, a + 1, 0, 1, 0))
sage: u in C and v in C
True
And the hamming weight of v = v-u is 3... Actually there are two algorithms in Sage and both of them fail
sage: LinearCode(G).minimum_distance(algorithm="guava")
5
sage: LinearCode(G).minimum_distance(algorithm="gap")
5
(edit: here I am wrong, the argument "guava" is considered only if the cardinality of the field is 2 or 3)
One possible reason is that it is not over a prime field.
Vincent
3 | No.3 Revision |
Hello,
Indeed there is a bug
sage: u = C((0, 0, 0, 0, 0, 0, 0))
sage: v = C((1, 0, 0, a + 1, 0, 1, 0))
sage: u in C and v in C
True
And the hamming weight of v = v-u is 3... Actually there are two algorithms in Sage and both of them fail
sage: LinearCode(G).minimum_distance(algorithm="guava")
5
sage: LinearCode(G).minimum_distance(algorithm="gap")
5
(edit: here I am wrong, the argument "guava" is considered only if the cardinality of the field is 2 or 3)
One possible reason is that it is not over a prime field.
Vincent
4 | No.4 Revision |
Hello,
Indeed there is The problem comes from the fact that your matrix does not have full rank (indeed it has rank 3 and 7 rows). If you use a bugfull rank matrix then you are done
sage: u C1 = C((0, 0, 0, 0, 0, 0, 0))
LinearCode(G)
sage: v C2 = C((1, 0, 0, a + 1, 0, 1, 0))
LinearCode(G[:3])
sage: u in C and v in C
C1 == C2
True
sage: C1.minimum_distance()
5
sage: C2.minimum_distance()
3
And I opened a trac ticket for that problem. It will be modified in the hamming weight of v = v-u is 3... Actually there are two algorithms in Sage and both of them failnext stable release. Thanks for your report!
sage: LinearCode(G).minimum_distance(algorithm="guava")
5
sage: LinearCode(G).minimum_distance(algorithm="gap")
5
One possible reason is that it is If you want to contribute to Sage, do not over hesitate to open a prime field.trac account and participate in the resolution of this problem.
Vincent
5 | No.5 Revision |
Hello,
The problem comes from the fact that your matrix does not have full rank (indeed it has rank 3 and 7 rows). If you use a full rank matrix then you are done
sage: C1 = LinearCode(G)
sage: C2 = LinearCode(G[:3])
sage: C1 == C2
True
sage: C1.minimum_distance()
5
sage: C2.minimum_distance()
3
I opened a the trac ticketticket #17452 for that problem. It will be modified in the next stable release. Thanks for your report!
If you want to contribute to Sage, do not hesitate to open a trac account and participate in the resolution of this problem.
Vincent