The calculation of a segment of eigenvalues and their corresponding eigenvectors of a Hermitian matrix or matrix pencil has many applications. A new density-matrix-based algorithm has been proposed recently and a software package FEAST has been developed. The density-matrix approach allows FEAST’s implementation to exploit a key strength of modern computer architectures, namely, multiple levels...

A major aspect of the FEAST programme of research into long-term software evolution processes has been the collection of metrics for evolving software products, and the examination of the trends over time in these metrics. Due to difficulties in collecting suitable metrics over the long timescales necessary to perform FEAST analyses, the selection of metrics has generally been pragmatic, relyin...

The contour-integral based eigensolvers are the recent efforts for computing the eigenvalues inside a given region in the complex plane. The best-known members are the Sakurai-Sugiura (SS) method, its stable version CIRR, and the FEAST algorithm. An attractive computational advantage of these methods is that they are easily parallelizable. The FEAST algorithm was developed for the generalized H...

of ECT Illustrates the Roles of Current Directionality, Polarity, and Electrode Configuration in Seizure Induction Timothy Spellman, Angel V Peterchev and Sarah H Lisanby* Division of Brain Stimulation and Therapeutic Modulation, Department of Psychiatry, Columbia University, New York State Psychiatric Institute, New York, NY, USA Electroconvulsive therapy (ECT) is a mainstay in the treatment o...

The FEAST eigenvalue algorithm is a subspace iteration algorithm that uses contour integration in the complex plane to obtain the eigenvectors of a matrix for the eigenvalues that are located in any user-defined search interval. By computing small numbers of eigenvalues in specific regions of the complex plane, FEAST is able to naturally parallelize the solution of eigenvalue problems by solvin...

INTRODUCTION Use of electroconvulsive therapy (ECT) is limited by cognitive disturbance. Focal electrically-administered seizure therapy (FEAST) is designed to initiate focal seizures in the prefrontal cortex. To date, no studies have documented the effects of FEAST on regional cerebral blood flow (rCBF). METHODS A 72 year old depressed man underwent three single photon emission computed tomo...

DEAR EDITOR The feast of sacrifice is a muslim tradition, celebrated by the muslims all around the world. Every year during the month of pilgrimage to Mecca (Hajj), the feast of sacrifice is celebrated. One specific part of this feast is to sacrifice animals such as sheep and cattle in the first three days of the feast. Most of the sacrifices were performed in the streets by non-professionals w...

OBJECTIVE Electroconvulsive therapy (ECT) is the most rapid and effective antidepressant treatment but with concerns about cognitive adverse effects. A new form of ECT, focal electrically administered seizure therapy (FEAST), was designed to increase the focality of stimulation and better match stimulus parameters with neurophysiology. We recently reported on the safety and feasibility of FEAST...

Calculating portions of eigenvalues and eigenvectors of matrices or matrix pencils has many applications. An approach to this calculation for Hermitian problems based on a density matrix has been proposed in 2009 and a software package called FEAST has been developed. The density-matrix approach allows FEAST’s implementation to exploit a key strength of modern computer architectures, namely, mu...

The linear FEAST algorithm is a method for solving linear eigenvalue problems. It uses complex contour integration to calculate the eigenvectors whose eigenvalues that are located inside some user-defined region in the complex plane. This makes it possible to parallelize the process of solving eigenvalue problems by simply dividing the complex plane into a collection of disjoint regions and cal...