qgs2

qgs2 is an open‑source software package designed to build and manipulate quality graph structures. It was introduced as the second major release of the original qgs project, which began development in 2014 by a team of researchers at the University of Oslo. The primary goal of qgs2 is to provide a high‑performance, flexible framework that can be used in computational geometry, spatial data analysis, and network optimization.

The core of qgs2 is a C++ library that implements algorithms for constructing planar graphs, performing planar embedding, and optimizing edge weights under quality constraints. The library exposes a clean API that can be accessed directly from C++ or wrapped for use in Python, allowing integration with scientific workflows. It supports graph serialization to common formats such as GraphML and JSON, and can read input from standard GIS coordinate files.

Usage is typically command‑line driven. The qgs2-cli tool accepts a variety of options: -i or --input specifies the source data file, -o or --output names the resulting graph file, while flags such as --optimize and --threshold control the strictness of quality constraints. A thorough set of tutorials and example scripts are provided with the source distribution to help new users get started quickly.

qgs2 is released under the MIT license, encouraging adoption in both academic research and commercial products that require reliable graph construction under quality constraints.