Opened 10 years ago

Last modified 3 months ago

## #13556 new defect

# vector(RR, QQ) stalls

Reported by: | Eviatar Bach | Owned by: | jason, was |
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Priority: | major | Milestone: | sage-9.8 |

Component: | linear algebra | Keywords: | |

Cc: | Merged in: | ||

Authors: | Reviewers: | ||

Report Upstream: | N/A | Work issues: | |

Branch: | Commit: | ||

Dependencies: | Stopgaps: |

### Description

The command vector(RR, QQ) never finishes executing.

### Change History (13)

### comment:1 Changed 10 years ago by

### comment:2 Changed 10 years ago by

To the best of my knowledge, sage currently does not handle infinite sequences. So the following also run indefinitely

sage: list(QQ) sage: tuple(QQ) sage: Sequence((1..)) sage: Sequence(ZZ) sage: Sequence(Partitons())

I've started a thread on sage-devel about how to proceed.

https://groups.google.com/forum/?fromgroups=#!topic/sage-devel/Pl14P2mr8N8

### comment:3 Changed 9 years ago by

Milestone: | sage-5.11 → sage-5.12 |
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### comment:4 Changed 9 years ago by

Milestone: | sage-6.1 → sage-6.2 |
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### comment:5 Changed 9 years ago by

Milestone: | sage-6.2 → sage-6.3 |
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### comment:6 Changed 8 years ago by

Milestone: | sage-6.3 → sage-6.4 |
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### comment:8 Changed 2 years ago by

Milestone: | sage-9.2 → sage-9.3 |
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### comment:9 Changed 21 months ago by

Milestone: | sage-9.3 → sage-9.4 |
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Sage development has entered the release candidate phase for 9.3. Setting a new milestone for this ticket based on a cursory review of ticket status, priority, and last modification date.

### comment:10 Changed 16 months ago by

Milestone: | sage-9.4 → sage-9.5 |
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### comment:11 Changed 12 months ago by

Milestone: | sage-9.5 → sage-9.6 |
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### comment:12 Changed 7 months ago by

Milestone: | sage-9.6 → sage-9.7 |
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### comment:13 Changed 3 months ago by

Milestone: | sage-9.7 → sage-9.8 |
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**Note:**See TracTickets for help on using tickets.

The reason this takes for ever is that Sage is trying to create the infinite vector

whose entries are an enumeration of the rationals. It's line 504 of

`sage/structure/sequence.py`

(sage-5.3):in which

`universe`

is`RR`

and`x`

is`QQ`

, that's hanging.An initial segment of this vector can created as