CHBGV man page on IRIX

Man page or keyword search:  
man Server   31559 pages
apropos Keyword Search (all sections)
Output format
IRIX logo
[printable version]



CHBGV(3F)							     CHBGV(3F)

NAME
     CHBGV - compute all the eigenvalues, and optionally, the eigenvectors of
     a complex generalized Hermitian-definite banded eigenproblem, of the form
     A*x=(lambda)*B*x

SYNOPSIS
     SUBROUTINE CHBGV( JOBZ, UPLO, N, KA, KB, AB, LDAB, BB, LDBB, W, Z, LDZ,
		       WORK, RWORK, INFO )

	 CHARACTER     JOBZ, UPLO

	 INTEGER       INFO, KA, KB, LDAB, LDBB, LDZ, N

	 REAL	       RWORK( * ), W( * )

	 COMPLEX       AB( LDAB, * ), BB( LDBB, * ), WORK( * ), Z( LDZ, * )

PURPOSE
     CHBGV computes all the eigenvalues, and optionally, the eigenvectors of a
     complex generalized Hermitian-definite banded eigenproblem, of the form
     A*x=(lambda)*B*x. Here A and B are assumed to be Hermitian and banded,
     and B is also positive definite.

ARGUMENTS
     JOBZ    (input) CHARACTER*1
	     = 'N':  Compute eigenvalues only;
	     = 'V':  Compute eigenvalues and eigenvectors.

     UPLO    (input) CHARACTER*1
	     = 'U':  Upper triangles of A and B are stored;
	     = 'L':  Lower triangles of A and B are stored.

     N	     (input) INTEGER
	     The order of the matrices A and B.	 N >= 0.

     KA	     (input) INTEGER
	     The number of superdiagonals of the matrix A if UPLO = 'U', or
	     the number of subdiagonals if UPLO = 'L'. KA >= 0.

     KB	     (input) INTEGER
	     The number of superdiagonals of the matrix B if UPLO = 'U', or
	     the number of subdiagonals if UPLO = 'L'. KB >= 0.

     AB	     (input/output) COMPLEX array, dimension (LDAB, N)
	     On entry, the upper or lower triangle of the Hermitian band
	     matrix A, stored in the first ka+1 rows of the array.  The j-th
	     column of A is stored in the j-th column of the array AB as
	     follows:  if UPLO = 'U', AB(ka+1+i-j,j) = A(i,j) for max(1,j-
	     ka)<=i<=j; if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for
	     j<=i<=min(n,j+ka).

									Page 1

CHBGV(3F)							     CHBGV(3F)

	     On exit, the contents of AB are destroyed.

     LDAB    (input) INTEGER
	     The leading dimension of the array AB.  LDAB >= KA+1.

     BB	     (input/output) COMPLEX array, dimension (LDBB, N)
	     On entry, the upper or lower triangle of the Hermitian band
	     matrix B, stored in the first kb+1 rows of the array.  The j-th
	     column of B is stored in the j-th column of the array BB as
	     follows:  if UPLO = 'U', BB(kb+1+i-j,j) = B(i,j) for max(1,j-
	     kb)<=i<=j; if UPLO = 'L', BB(1+i-j,j)    = B(i,j) for
	     j<=i<=min(n,j+kb).

	     On exit, the factor S from the split Cholesky factorization B =
	     S**H*S, as returned by CPBSTF.

     LDBB    (input) INTEGER
	     The leading dimension of the array BB.  LDBB >= KB+1.

     W	     (output) REAL array, dimension (N)
	     If INFO = 0, the eigenvalues in ascending order.

     Z	     (output) COMPLEX array, dimension (LDZ, N)
	     If JOBZ = 'V', then if INFO = 0, Z contains the matrix Z of
	     eigenvectors, with the i-th column of Z holding the eigenvector
	     associated with W(i). The eigenvectors are normalized so that
	     Z**H*B*Z = I.  If JOBZ = 'N', then Z is not referenced.

     LDZ     (input) INTEGER
	     The leading dimension of the array Z.  LDZ >= 1, and if JOBZ =
	     'V', LDZ >= N.

     WORK    (workspace) COMPLEX array, dimension (N)

     RWORK   (workspace) REAL array, dimension (3*N)

     INFO    (output) INTEGER
	     = 0:  successful exit
	     < 0:  if INFO = -i, the i-th argument had an illegal value
	     > 0:  if INFO = i, and i is:
	     <= N:  the algorithm failed to converge:  i off-diagonal elements
	     of an intermediate tridiagonal form did not converge to zero; >
	     N:	  if INFO = N + i, for 1 <= i <= N, then CPBSTF
	     returned INFO = i: B is not positive definite.  The factorization
	     of B could not be completed and no eigenvalues or eigenvectors
	     were computed.

									Page 2

[top]

List of man pages available for IRIX

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net