Parallelize Possible Periods functions for Projective Morphisms

[drose]

Parallelize Possible Periods functions for Projective Morphisms

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​6cf68fb

Parallelized all_rational_preimages function

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​500a0ca

Parallelized possible_periods function

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​8ab83fd

Fixed paralleization of all_rational_preimages

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​69dd970

Changed doctest to reflect changes

[bhutz]

These two changes looks fine. However, there is a third place that should be done in parallel.

periodic_points=self.lift_to_rational_periodic(pos_points,B)

in self.rational_periodic_points()

Also, it is convention not to use CamelCase variables names. (i.e. parallelData, possiblePeriods should be not have the capital in them).

I'm also marking 15966 as a dependency since without the cleanup of the child process these create too many child process to function well.

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​db46450	Merge branch 'u/drose/ticket/15966' of git://trac.sagemath.org/sage into ticket/15920
​0fe665b	Removed camelCase variables.

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​d51711c	Parallelized rational_periodic_points function.
​ec44863	Changed documentation and doctests because of parallelization.

[bhutz]

Remember to set the status on tickets when it is ready for review again, but it is still needs_work so I'll leave it.

The functionality all checks out on my tests. However, with that last parallelization bit, there are 3 more doctests that are failing due to point order in projective_morphism.py. So you should sort those as well.

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​8bcc13a

Fixed bug in rational_periodic_points function.

[bhutz]

This still has the 3 doctest failures due to sorting from

sage -t --long projective_morphism.py

[bhutz]

Actually, this is fine, I had failed to pull down all the commits.

[bhutz]

I'm getting some weird errors when I run the possible_periods over and over again (even on the same function). It seems to be somewhat random which error and whether or not an error occurs). I may or may not have corrupted my sage, but I don't want to leave this positive_review until I resolve it.

Errors like

Traceback (most recent call last):
...
TypeError: number of arguments does not match number of variables in parent

and

 Traceback (most recent call last):
  ....
TypeError: unsupported operand parent(s) for '*': 'Finite Field of size 2' and 'Finite Field of size 13'

[vbraun]

I had it already tested and it worked on the buildbot. Reopen if you can reproduce your failure...