riklund / matrixutils

Some utilities for creating binary matrices from other binary formats, and performing a Jacobi eigenvalue calculation.

#Matrix utility software

Consists of three different subprograms:

##Purify Takes two binary square matrix objects of the form gF + dI where g and d are scalars, F is a full matrix and I is a diagonal matrix, and creates a binary object which can be used to construct other matrix of the form gF + dI for any g.

###Format of input matrix: In order, the content of an input binary file should be the following:

1. Two unsigned integers, n and m, describing the dimensions of the matrix. Requirement: n = m since the matrix should be square.
2. n*n complex, the content of the matrix, row by row.
3. An unsigned long long with the value 38198464.

##ConstructMatrix Operates on the output from Purify to construct a matrix on the form gF + dI.

##Jacobi Operates on the output from ConstructMatrix, and finds the eigenvalue and eigenvector with the largest overlap of a vector with a component in a given direction.

#Note

At no point in any of the programs the full matrices are loaded into memory. If the matrices are of dimension n x n, the memory usage is O(n) with a small constant factor.