pentapy 0.1.1

pentapy: A toolbox for pentadiagonal matrizes.

Welcome to pentapy

Purpose

pentapy is a toolbox to deal with pentadiagonal matrices in Python.

Installation

The package can be installed via pip. On Windows you can install WinPython to get Python and pip running.

pip install pentapy

References

The solver is based on the algorithms PTRANS-I and PTRANS-II presented by Askar et al. 2015.

Examples

Solving a pentadiagonal linear equation system

This is an example of how to solve a LES with a pentadiagonal matrix.

import numpy as np
from pentapy import solve
size = 1000
# create a flattened pentadiagonal matrix
M_flat = (np.random.random((5, size)) - 0.5) * 1e-5
V = np.random.random(size) * 1e5
# solve the LES
X = solve(M_flat, V, is_flat=True)

# create the corresponding matrix for checking
M = (
     np.diag(M_flat[0, :-2], 2)
     + np.diag(M_flat[1, :-1], 1)
     + np.diag(M_flat[2, :], 0)
     + np.diag(M_flat[3, 1:], -1)
     + np.diag(M_flat[4, 2:], -2)
)
# calculate the error
print(np.max(np.abs(np.dot(M, X) - V)))

This should give something like:

4.257890395820141e-08

Requirements:

• NumPy >= 1.13.0

Contact

You can contact us via [e-mail].

License

GPL © 2019