Opened 5 years ago
Closed 5 years ago
#17578 closed defect (fixed)
Use Parent/Element for Manin symbols
Reported by:  pbruin  Owned by:  

Priority:  major  Milestone:  sage6.5 
Component:  modular forms  Keywords:  Manin symbol 
Cc:  jdemeyer, jpflori, was  Merged in:  
Authors:  Peter Bruin, Travis Scrimshaw  Reviewers:  Travis Scrimshaw, Peter Bruin 
Report Upstream:  N/A  Work issues:  
Branch:  286e475 (Commits)  Commit:  286e4756e2bb1e5657611d505ec5d7d6f99f3c36 
Dependencies:  Stopgaps: 
Description (last modified by )
The classes ManinSymbolList
and ManinSymbol
(in sage.modular.modsym.manin_symbols
) do not inherit from Parent
and Element
. We fix this and make ManinSymbolList
a parent in the category FiniteEnumeratedSets
.
To prevent a measurable slowdown, the class ManinSymbol
is converted to Cython.
This is a dependency of #10513.
Change History (19)
comment:1 Changed 5 years ago by
 Branch set to u/pbruin/17578ManinSymbol_Parent_Element
 Commit set to a9da0487574bd6c9e31743929de1a9ae1b476cdb
 Status changed from new to needs_review
comment:2 followup: ↓ 3 Changed 5 years ago by
 Branch changed from u/pbruin/17578ManinSymbol_Parent_Element to u/tscrim/manin_symbol_parent17578
 Commit changed from a9da0487574bd6c9e31743929de1a9ae1b476cdb to 9cf191b8faf45f97855e5612ed81d7a3988c5cb4
 Reviewers set to Travis Scrimshaw
I've made some more substantial changes making ManinSymbolList
a proper parent in FiniteEnumeratedSets
. In particular, there is a backwards incompatible change in that m[i]
returns a ManinSymbol
instance (of m
) rather than a tuple. Also I changed the _list
attribute to _symbol_list
since FiniteEnumeratedSets
uses _list
internally. Lastly I've added a method symbol_list
to get the explicit list of symbols (the indexing tuples).
I'm thinking we should post something to sagedevel stating this (proposed) change. Sound good?
New commits:
c070145  Merge branch 'u/pbruin/17578ManinSymbol_Parent_Element' of trac.sagemath.org:sage into u/tscrim/manin_symbol_parent17578

9cf191b  More changes towards a proper parent class.

comment:3 in reply to: ↑ 2 Changed 5 years ago by
Replying to tscrim:
I've made some more substantial changes making
ManinSymbolList
a proper parent inFiniteEnumeratedSets
. In particular, there is a backwards incompatible change in thatm[i]
returns aManinSymbol
instance (ofm
) rather than a tuple. Also I changed the_list
attribute to_symbol_list
sinceFiniteEnumeratedSets
uses_list
internally. Lastly I've added a methodsymbol_list
to get the explicit list of symbols (the indexing tuples).I'm thinking we should post something to sagedevel stating this (proposed) change. Sound good?
I don't mind too much, but given that this ticket is a dependency of #10513, which already has positive review, wouldn't it make sense to do this on a different ticket? (I currently don't have enough time to review your changes.)
comment:4 Changed 5 years ago by
 Dependencies set to #15015
This will almost certainly conflict with the alreadymerged #15015.
comment:5 Changed 5 years ago by
 Dependencies changed from #15015 to #17579
comment:6 Changed 5 years ago by
comment:7 Changed 5 years ago by
comment:8 Changed 5 years ago by
 Commit changed from 9cf191b8faf45f97855e5612ed81d7a3988c5cb4 to 57a425901538723e212815ab1e84908ff992cf40
Branch pushed to git repo; I updated commit sha1. Last 10 new commits:
7725122  Cosmetic changes

6957f17  Merge remotetracking branch 'origin/develop' into ticket/15015

aca71cb  Upgrade to mpir2.7.0alpha12

67babeb  Fix doctests due to changed xgcd results

8c7fbbd  Reenable "not tested" test from #4357

aefe0eb  Upgrade to MPIR 2.7.0alpha12

3d583af  Merge remotetracking branch 'origin/develop' into ticket/15015

d97c066  Rename source directory

d647df8  Trac 17579: move ManinSymbol class

57a4259  Merge branch 'u/jdemeyer/ticket/17579' of trac.sagemath.org:sage into u/tscrim/manin_symbol_parent17578

comment:9 Changed 5 years ago by
I merged in #17579, but kept the version from here.
comment:10 Changed 5 years ago by
 Branch changed from u/tscrim/manin_symbol_parent17578 to u/pbruin/17578ManinSymbol_Parent_Element
 Commit changed from 57a425901538723e212815ab1e84908ff992cf40 to e59b940b36c40cca506f7740a480c47369920309
In the meantime I already rebased the branch (I think this is a better solution than merging in this case) and reverted the more substantial changes from Travis's commit, so that this ticket can be merged as soon as possible in view of #10513.
comment:11 Changed 5 years ago by
I strongly disagree with doing this (IMO) dirty hack of parents just to merge it quickly. It creates parents without a category and elements not created from the parent, both of which are abuses of Parent
.
Also from my understanding, since this branch was published and I based my branch on it, it was not good to rebase the branch. Merge commits don't hurt anyone.
comment:12 Changed 5 years ago by
 Branch changed from u/pbruin/17578ManinSymbol_Parent_Element to u/tscrim/manin_symbol_parent17578
 Cc was added
 Commit changed from e59b940b36c40cca506f7740a480c47369920309 to 57a425901538723e212815ab1e84908ff992cf40
I'm creating the following for the test:
sage: from sage.modular.modsym.manin_symbols import ManinSymbolList_gamma0 sage: m = ManinSymbolList_gamma0(5,8)
Previously we have:
sage: %time L = m.manin_symbol_list() CPU times: user 560 µs, sys: 84 µs, total: 644 µs Wall time: 494 µs sage: %time L = m.manin_symbol_list() CPU times: user 48 µs, sys: 4 µs, total: 52 µs Wall time: 68.9 µs
With my branch:
sage: %time L = m.manin_symbol_list() CPU times: user 644 µs, sys: 90 µs, total: 734 µs Wall time: 747 µs sage: %time L = m.manin_symbol_list() CPU times: user 56 µs, sys: 7 µs, total: 63 µs Wall time: 64.8 µs
With Peter's branch:
sage: %time L = m.manin_symbol_list() CPU times: user 792 µs, sys: 99 µs, total: 891 µs Wall time: 828 µs sage: %time L = m.manin_symbol_list() CPU times: user 49 µs, sys: 6 µs, total: 55 µs Wall time: 66 µs
So there is a slowdown with creating the instances of ManinSymbol
that comes from the new branch and Peters by creating instances of Element
. Hence this is a slowdown we might just have to deal with (assuming one is actually wanting the ManinSymbol
, not the indexing tuple which can be grabbed by symbol_list
).
New commits:
6494bcd  Trac 17578: move ManinSymbol class (1)

dcf9d35  Trac 17578: move ManinSymbol class (2)

a9da048  Trac 17578: use Parent/Element for Manin symbols

c070145  Merge branch 'u/pbruin/17578ManinSymbol_Parent_Element' of trac.sagemath.org:sage into u/tscrim/manin_symbol_parent17578

9cf191b  More changes towards a proper parent class.

57a4259  Merge branch 'u/jdemeyer/ticket/17579' of trac.sagemath.org:sage into u/tscrim/manin_symbol_parent17578

comment:13 followup: ↓ 14 Changed 5 years ago by
If I'm reading your test, that's not just "a slowdown...we might just have to deal with", it's an epic slowdown, by a full factor of 10. Am I reading that right? If so, then this is definitely seriously worrisome.
comment:14 in reply to: ↑ 13 Changed 5 years ago by
Replying to was:
If I'm reading your test, that's not just "a slowdown...we might just have to deal with", it's an epic slowdown, by a full factor of 10. Am I reading that right? If so, then this is definitely seriously worrisome.
The first line is the actual creation, the second is when the caching comes into effect. However the slowdown is by ~1.4x due to the overhead. Thus if we want to fix the probthese without the overhead from the category, we need an entirely different approach. Do you think you could run a timing in a more realistic computation or post such a computation?
comment:15 Changed 5 years ago by
 Branch changed from u/tscrim/manin_symbol_parent17578 to u/pbruin/17578ManinSymbol_Parent_Element
 Commit changed from 57a425901538723e212815ab1e84908ff992cf40 to 286e4756e2bb1e5657611d505ec5d7d6f99f3c36
 Dependencies #17579 deleted
 Description modified (diff)
Here is a new branch incorporating my original fix, Travis's improvements, and a restructuring of the module sage.modular.modsym.manin_symbols
into two new modules sage.modular.modsym.manin_symbol
(Cython) and sage.modular.modsym.manin_symbol
(Python).
The creation of the list in Travis's example goes down from 191 µs to 150 µs on the system on which I tested this.
(I have decided to rebase my branch; it has been inactive for months and I wanted to start with a clean slate. In particular, I found the duplicate commits in the Git history extremely annoying.)
comment:16 followup: ↓ 17 Changed 5 years ago by
 Reviewers changed from Travis Scrimshaw to Travis Scrimshaw, Peter Bruin
Overall I'm happy with the changes (especially the speedup, which was the sticking point for getting this in). Quick question, could any of those methods for the ManinSymbol
class be declared cpdef
and get a speed boost? If not (or you don't think it's necessary to do now), you can set this to a positive review.
comment:17 in reply to: ↑ 16 Changed 5 years ago by
 Status changed from needs_review to positive_review
Replying to tscrim:
Overall I'm happy with the changes (especially the speedup, which was the sticking point for getting this in).
Thanks!
Quick question, could any of those methods for the
ManinSymbol
class be declaredcpdef
and get a speed boost? If not (or you don't think it's necessary to do now), you can set this to a positive review.
I prefer to do this later if and when it becomes necessary.
comment:18 Changed 5 years ago by
Alright. Thanks for your work on this (and on improving the modules!!!).
comment:19 Changed 5 years ago by
 Branch changed from u/pbruin/17578ManinSymbol_Parent_Element to 286e4756e2bb1e5657611d505ec5d7d6f99f3c36
 Resolution set to fixed
 Status changed from positive_review to closed
The only real changes are in commit
a9da048
; the first two move the classManinSymbol
up in the file to allowElement = ManinSymbol
inManinSymbolList
.