# Circulant Algebra codes

### David F. Gleich, Chen Greif, and James M. Varah

The power and Arnoldi methods in an algebra of circulants.

These codes are research prototypes and may not work for you.
More documentation and examples will be available soon.

## Overview

The package is organized by directory

camat
The root directory for the package. This includes many routines, such as the power method cpowmtd.m, the Arnoldi method carnoldi.m, and Lanczos and Golub-Kahan bidiagonalization routines as well clanczos.m and cgolubkubd.m. This directory also includes constructors such as cazeros, caones, carand, carandi, carandn.
camat/@camat
The files for the Matlab class implemening the circulant algebra.
camat/experiments
THe directory that holds our experiments.
camat/kilmer
Many of the same operations, implemented as described in Kilmer, Martin, and Perrone. …

## Usage

With a recent version of Matlab (2009b/2010a used for development), the best way to use the package is to open Matlab, navigate to the camat directory, and then execute the command

>>> type example_1.m

This will show a short demo of how to use the package.

## Experiments

ExperimentDescriptionFigure
periodic_pede/periodic_pde.mRun the experiment with Laplace’s equationFigure 7, 8
example_1.mShow a simple usage example

There are many other undocumented experimental codes in the experiments directory as well.