— Loadable Function: [count, h, parent, post, r] = symbfact (s, typ, mode)

Performs a symbolic factorization analysis on the sparse matrix s. Where

s

s is a complex or real sparse matrix.

typ

Is the type of the factorization and can be one of

sym

Factorize s. This is the default.

col

Factorize s' * s.

row

Factorize s * s'.

lo

Factorize s'

mode

The default is to return the Cholesky factorization for r, and if mode is 'L', the conjugate transpose of the Choleksy factorization is returned. The conjugate transpose version is faster and uses less memory, but returns the same values for count, h, parent and post outputs.

The output variables are

count

The row counts of the Cholesky factorization as determined by typ.

h

The height of the elimination tree.

parent

The elimination tree itself.

post

A sparse boolean matrix whose structure is that of the Cholesky factorization as determined by typ.