Dear Marcelo, A couple of suggestions, I find that forgotten math for me can be recalled by calling up: http://www.sosmath.com/ For specific derive related problems you might try to send a specific concern to the attention of the authors: The QR method for finding eigenvalues of large square matrices written by Terence Etchells & Carl Leinbach (whilst at LJMU on sabbatical) School of Computing and Mathematical Sciences Department of Computer Science Liverpool John Moores University Gettysburg College Liverpool Gettysburg PA UK USA [log in to unmask] [log in to unmask] ________________________________________________________________________________ _____________________________ Hessenberg Matrix HESSENBERG(A) This function converts any square matrix A into upper Hessenberg form. That is a matrix which has zeros below the sub diagonal, but has the same eigenvalues as A. ************************************************** On flâne sur l'avenue de Jean-Jaurès, et comme Paul Langevin, on essaie de se poser des questions. --- Mike Law ----- Original Message ----- From: "Francisco Marcelo Fernandez" <[log in to unmask]> To: <[log in to unmask]> Sent: Monday, June 02, 2003 5:35 PM Subject: Problem with eigenvals Dear Derivers, I have some problems when using eigenvals.dfw which are shown in the attached file. I hope somebody will tell me what I am doing wrong. Thanks in advance, Marcelo. Francisco M. Fernández, CEQUINOR, Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calle 47 y 115, Casilla de Correo 962, 1900 La Plata, Argentina. Phone/fax: (54-221) 482-2643/424-0172 E-mail [log in to unmask] [log in to unmask] [log in to unmask] http://www.conicet.gov.ar/webue/cequinor/mick.htm -------------------------------------------------------------------------------- --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.486 / Virus Database: 284 - Release Date: 29/05/03