# Curver¶

Curver is a program for performing calculations in the curve complex. It implements the Bell–Webb algorithm [BellWebb16] to determine the Nielsen–Thurston type of a mapping class. This algorithm runs in polynomial time but the constants involved currently make this implementation impractical.

Curver officially supports Python 2.7 and 3.4 – 3.6. It also runs on PyPy and Sage.

Note

The use of **Python 3** is *highly* preferred over Python 2.
Consider upgrading your applications and infrastructure if you find yourself *still* using Python 2 in production today.
If you are using Python 3, congratulations — you are indeed a person of excellent taste. — *Kenneth Reitz*

A taste of curver:

```
>>> S = curver.load(0, 5)
>>> S('s_0.s_1.s_0') == S('s_1.s_0.s_1')
True
>>> S('S_2.S_3.S_4').is_periodic()
True
```

## Features¶

- Performs Nielsen–Thurston classification of mapping classes.
- Solves the word problem for mapping class groups.
- Computes the asymptotic translation length of mapping classes on the curve complex.
- Computes geodesics in the curve complex.
- Computes the action of mapping classes on H_1.
- Determines the topological type of multicurves.

## The User Guide¶

This part of the documentation, which is mostly prose, begins with some background information about Curver, then focuses on step-by-step instructions for getting the most out of Curver.

## The API Documentation¶

If you are looking for information on a specific function, class, or method, this part of the documentation is for you.

## The Contributor Guide¶

If you want to contribute to the project, this part of the documentation is for you.

There are no more guides. You are now guideless. Good luck.