Skip to main content

QDLDL, a free LDL factorization routine.

Project description

qdldl-python

github actions

Python interface to the QDLDL free LDL factorization routine for quasi-definite linear systems: Ax = b.

Installation

This package can be directly installed via pip,

pip install qdldl

Usage

Initialize the factorization with

import qdldl
F = qdldl.Solver(A)

where A must be a square quasi-definite matrix in scipy sparse CSC format.

The algorithm internally converts the matrix into upper triangular format. If A is already upper-triangular, you can specify it with the argument upper=True to the qdldl.Solver constructor.

To solve the linear system for a right-hand side b, just write

x = F.solve(b)

To update the factorization without changing the sparsity pattern of A you can run

F.update(A_new)

where A_new is a sparse matrix in CSR format with the same sparsity pattern as A.

The algorithm internally converts A_new into upper triangular format. If A_new is already upper-triangular, you can specify it with the argument upper=True to the F.update function.

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

qdldl-0.1.5.post2.tar.gz (69.1 kB view hashes)

Uploaded source

Built Distributions

qdldl-0.1.5.post2-cp310-cp310-win_amd64.whl (83.8 kB view hashes)

Uploaded cp310

qdldl-0.1.5.post2-cp39-cp39-win_amd64.whl (83.3 kB view hashes)

Uploaded cp39

qdldl-0.1.5.post2-cp38-cp38-win_amd64.whl (83.7 kB view hashes)

Uploaded cp38

qdldl-0.1.5.post2-cp37-cp37m-win_amd64.whl (84.4 kB view hashes)

Uploaded cp37

qdldl-0.1.5.post2-cp36-cp36m-win_amd64.whl (84.5 kB view hashes)

Uploaded cp36

Supported by

AWS AWS Cloud computing Datadog Datadog Monitoring Facebook / Instagram Facebook / Instagram PSF Sponsor Fastly Fastly CDN Google Google Object Storage and Download Analytics Huawei Huawei PSF Sponsor Microsoft Microsoft PSF Sponsor NVIDIA NVIDIA PSF Sponsor Pingdom Pingdom Monitoring Salesforce Salesforce PSF Sponsor Sentry Sentry Error logging StatusPage StatusPage Status page