This manual gives an introduction to the use of JADAMILU,
a set of Fortran 77 routines to compute selected eigenvalues and associated
eigenvectors of large scale real symmetric or complex Hermitian matrices.
Generalized eigenvalue problems with positive definite mass matrix can
also be solved.
The eigenvalues sought can either be the
smallest ones or those closest to some specified target
inside the spectrum. The package is based on the
Jacobi-Davidson method.
Key features are modest memory requirements, robust
convergence to accurate solutions, and the automatic setup of an
in-built preconditioner. On the other
hand, the program is flexible and easy to use by non-experts.
If the matrix is sparse and explicitly available, the user
can simply pass it to the program and let JADAMILU compute the desired
eigenvalues. If not, then a crude sparse approximation which may even
be diagonal, can be passed. In the latter case the user only needs
to define a routine that performs matrix-vector products.
and Yvan Notay
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