bigger

For studying big mapping classes


Keywords
infinite, surface, MCG
License
MIT
Install
pip install bigger==0.3.1

Documentation

Bigger

PyPI version PyPI license Github build status

Bigger is a program for computing big mapping classes and their actions on non-compact laminations via ideal triangulation coordinates. It's like flipper and curver, but can handle infinite-type surfaces by being lazy about the computations it performs.

Bigger officially supports Python 3.7 -- 3.9.

An arc on the ladder surface

Quickstart

Bigger is available on PyPI, so it can be installed via:

$ pip install bigger --user --upgrade

Once installed, try it inside of Python:

>>> import bigger
>>> S = bigger.load.spotted_ladder()  # The infinite-genus two-ended surface

# Let's make a finite curve
>>> c = S.triangulation({(0, 5): 1, (0, 6): 1})
>>> c
Lamination (0, 5): 1, (0, 6): 1

# Let's make an infinite lamination
>>> a = S.triangulation(lambda e: 2 if e[1] in {2, 3, 4, 6} else 0)
>>> a
Infinitely supported lamination (0, 0): 0, (0, 1): 0, (0, 2): 2, (0, 3): 2, (0, 4): 2, (0, 5): 0, (0, 6): 2, (0, 7): 0, (0, 8): 0, (-1, 0): 0 ...

# Let's make the picture at the top
>>> b = S('b{n >= 0}.a[2].a.a')(a)  # Apply some mapping classes
# The edges that we are interested in
>>> edges = [(i, j) for i in range(-1, 2) for j in range(2, 9)] + [(i, 0) for i in range(2)]
>>> b.draw(edges, layout=S, w=800)

External Links