On behalf of the PySAL development team, I'm happy to announce the

official release of PySAL 1.6.

PySAL is a library of tools for spatial data analysis and

geocomputation written in Python. PySAL 1.6, the seventh official

release of PySAL brings the following key enhancements:

### Spatial weights (weights)

 * Optimized contiguity builder

 * Explicit checks for disconnected observations (islands)

 * Lightweight sparse weights class

 * Handle coincident points in construction of distance based weights 

 * Optimized construction of knn weights

### Spatial regression (spreg)

 * Chow test on spatial autoregressive coefficient in error, lag and combination regime models

 * Kernel based weights specialized for HAC estimators

 * Group-wise heteroskedasticity correction for OLS models with regimes

 * Optimal GMM estimator to account for heteroskedasticity in TSLS models with regimes

### Spatial inequality (inequality)

 * Spatial decomposition of the Gini coefficient

 

### Computational geometry (cg)

 * Robust segment intersection tests

among the 246 commits and bug fixes since the last release, 6 months ago.

In addition, 1.6 marks the first release since PySAL moved from Google Code to GitHub

## PySAL modules

    * pysal.core — Core Data Structures and IO

    * pysal.cg — Computational Geometry

    * pysal.esda — Exploratory Spatial Data Analysis

    * pysal.inequality — Spatial Inequality Analysis

    * pysal.spatial_dynamics — Spatial Dynamics

    * pysal.spreg - Regression and Diagnostics

    * pysal.region — Spatially Constrained Clustering

    * pysal.weights — Spatial Weights

    * pysal.FileIO — PySAL FileIO: Module for reading and writing various file types in a Pythonic way

## Downloads

Source distributions are available at

Binary installers are availble from the [GeoDa Center for Geospatial Analysis and Computation](https://geodacenter.asu.edu/projects/pysal)

PySAL can also be installed with pip or easy_install.

## Documentation

The documentation site is here

## Web sites

PySAL's home is here

The developer's site is here

## Mailing Lists

Please see the developer's list here

Help for users is here

## Bug reports and feature requests

To search for or report bugs, as well as request enhancements, please see

## License information

See the file "LICENSE.txt" for information on the history of this

software, terms & conditions for usage, and a DISCLAIMER OF ALL

WARRANTIES.

Many thanks to [all who contributed!](https://github.com/pysal/pysal/blob/master/THANKS.txt)

Serge, on behalf of the PySAL development team.