problems installing TOPCOM for triangulations?

[Ursula]

I'm running sage-5.10.rc0.

When I evaluate the following code:

p = ReflexivePolytope(3,2)
points = p.points().columns()
pointConfig = PointConfiguration(points)
regular = pointConfig.restrict_to_regular_triangulations(True)
regular

I get the error:

You must install TOPCOM to test for regularity.

But I have installed TOPCOM, using the command install_package('TOPCOM') in the notebook!

Any ideas what is going on?  The full traceback on my error message is:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "_sage_input_12.py", line 10, in <module>
    exec compile(u'open("___code___.py","w").write("# -*- coding: utf-8 -*-\\n" + _support_.preparse_worksheet_cell(base64.b64decode("cCA9IFJlZmxleGl2ZVBvbHl0b3BlKDMsMikKcG9pbnRzID0gcC5wb2ludHMoKS5jb2x1bW5zKCkKcG9pbnRDb25maWcgPSBQb2ludENvbmZpZ3VyYXRpb24ocG9pbnRzKQpyZWd1bGFyID0gcG9pbnRDb25maWcucmVzdHJpY3RfdG9fcmVndWxhcl90cmlhbmd1bGF0aW9ucyhUcnVlKQpyZWd1bGFy"),globals())+"\\n"); execfile(os.path.abspath("___code___.py"))
  File "", line 1, in <module>
    
  File "/tmp/tmpVZpwc_/___code___.py", line 6, in <module>
    regular = pointConfig.restrict_to_regular_triangulations(True)
  File "/home/whitchua/sage-5.10.rc0/local/lib/python2.7/site-packages/sage/geometry/triangulation/point_configuration.py", line 790, in restrict_to_regular_triangulations
    star=self._star)
  File "classcall_metaclass.pyx", line 330, in sage.misc.classcall_metaclass.ClasscallMetaclass.__call__ (build/cythonized/sage/misc/classcall_metaclass.c:1224)
  File "/home/whitchua/sage-5.10.rc0/local/lib/python2.7/site-packages/sage/geometry/triangulation/point_configuration.py", line 311, in __classcall__
    .__classcall__(cls, points, connected, fine, regular, star, defined_affine)
  File "cachefunc.pyx", line 992, in sage.misc.cachefunc.WeakCachedFunction.__call__ (build/cythonized/sage/misc/cachefunc.c:5394)
  File "/home/whitchua/sage-5.10.rc0/local/lib/python2.7/site-packages/sage/structure/unique_representation.py", line 447, in __classcall__
    instance = typecall(cls, *args, **options)
  File "classcall_metaclass.pyx", line 518, in sage.misc.classcall_metaclass.typecall (build/cythonized/sage/misc/classcall_metaclass.c:1586)
  File "/home/whitchua/sage-5.10.rc0/local/lib/python2.7/site-packages/sage/geometry/triangulation/point_configuration.py", line 342, in __init__
    raise ValueError, 'You must install TOPCOM to test for regularity.'
ValueError: You must install TOPCOM to test for regularity.

--Ursula Whitcher.

[William Stein]

On Mon, Jul 1, 2013 at 1:19 PM, Ursula <whit...@uwec.edu> wrote:
> I'm running sage-5.10.rc0.
>
> When I evaluate the following code:
>
> p = ReflexivePolytope(3,2)
> points = p.points().columns()
> pointConfig = PointConfiguration(points)
> regular = pointConfig.restrict_to_regular_triangulations(True)
> regular
>
> I get the error:
>
> You must install TOPCOM to test for regularity.

For what it is worth, when I run the above on
https://cloud.sagemath.com, where Sage is v 5.10 and the TOPCOM
packaged is installed, I get this output:

Exception pexpect.ExceptionPexpect: ExceptionPexpect() in <generator
object _TOPCOM_exec at 0x9185c30> ignored
A point configuration in QQ^3 consisting of 6 points. The
triangulations of this point configuration are assumed to be
connected, not necessarily fine, regular.

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--
William Stein
Professor of Mathematics
University of Washington
http://wstein.org

[Volker Braun]

The interface checks whether the utility program "points2placingtriang" from TOPCOM is available, and didn't find it in your install. Do you have Sage's current spkg of TOPCOM installed or some other version?

Just for the record, you almost certainly want 

regular.restrict_to_star_triangulations([0,0,0])

as well.

[Ursula Whitcher]

On 7/1/2013 8:26 PM, Volker Braun wrote:
> The interface checks whether the utility program "points2placingtriang"
> from TOPCOM is available, and didn't find it in your install. Do you
> have Sage's current spkg of TOPCOM installed or some other version?

I ran

install_package('TOPCOM')

from the notebook command line, so I have whatever version installed
automatically.

> Just for the record, you almost certainly want
>
> regular.restrict_to_star_triangulations([0,0,0])
>
> as well.

Not actually, I'm not trying to construct a fan for a toric variety :)

UAW

[Volker Braun]

You need to restart the notebook since the test output is cached...

[Volker Braun]

This sounds even worse, the triangulation module is pure python but you got an exception ignored which must have come from some C/Cython code. 

[Ursula Whitcher]

On 7/1/2013 8:42 PM, Volker Braun wrote:
> You need to restart the notebook since the test output is cached...

Yes, that seems to have solved the problem. You might want to add a
note to this effect in the documentation for Triangulations of a point
configuration.

--Ursula.

[Volker Braun]

I agree that this is a usability wart... though really I think the whole idea of installing further components while Sage is running is a bad design choice. For example, if you end up modifying shared libraries that are currently mmaped then bad things will happen.

[Ursula Whitcher]

On 7/2/2013 1:51 PM, Volker Braun wrote:
> I agree that this is a usability wart... though really I think the whole
> idea of installing further components while Sage is running is a bad
> design choice. For example, if you end up modifying shared libraries
> that are currently mmaped then bad things will happen.

So why doesn't TOPCOM install with Sage by default?

UAW

[Volker Braun]

On Wednesday, July 3, 2013 11:06:02 AM UTC-4, Ursula wrote:

So why doesn't TOPCOM install with Sage by default?

Its a relatively large package for relatively small feature (regularity testing of generated triangulations and finding triangulations that are not connected by flips to the regular triangulations). The regularity testing could easily done in Python/PPL, too---the toric Kahler cone stuff basically has all the necessary code. 

TOPCOM is faster at enumerating but incurs a constant slowdown for going through a pexpect interface.