👤
Home Man
Search
Today's Posts
Register

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:
Select Section of Man Page:
Select Man Page Repository:

RedHat 9 (Linux i386) - man page for sspgv (redhat section l)

SSPGV(l)					)					 SSPGV(l)

NAME
       SSPGV  -  compute all the eigenvalues and, optionally, the eigenvectors of a real general-
       ized symmetric-definite eigenproblem, of the form  A*x=(lambda)*B*x,  A*Bx=(lambda)*x,  or
       B*A*x=(lambda)*x

SYNOPSIS
       SUBROUTINE SSPGV( ITYPE, JOBZ, UPLO, N, AP, BP, W, Z, LDZ, WORK, INFO )

	   CHARACTER	 JOBZ, UPLO

	   INTEGER	 INFO, ITYPE, LDZ, N

	   REAL 	 AP( * ), BP( * ), W( * ), WORK( * ), Z( LDZ, * )

PURPOSE
       SSPGV computes all the eigenvalues and, optionally, the eigenvectors of a real generalized
       symmetric-definite  eigenproblem,  of  the  form  A*x=(lambda)*B*x,  A*Bx=(lambda)*x,   or
       B*A*x=(lambda)*x. Here A and B are assumed to be symmetric, stored in packed format, and B
       is also positive definite.

ARGUMENTS
       ITYPE   (input) INTEGER
	       Specifies the problem type to be solved:
	       = 1:  A*x = (lambda)*B*x
	       = 2:  A*B*x = (lambda)*x
	       = 3:  B*A*x = (lambda)*x

       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.

       AP      (input/output) REAL array, dimension
	       (N*(N+1)/2) On entry, the upper or lower  triangle  of  the  symmetric  matrix  A,
	       packed  columnwise in a linear array.  The j-th column of A is stored in the array
	       AP as follows: if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;  if  UPLO	=
	       'L', AP(i + (j-1)*(2*n-j)/2) = A(i,j) for j<=i<=n.

	       On exit, the contents of AP are destroyed.

       BP      (input/output) REAL array, dimension (N*(N+1)/2)
	       On entry, the upper or lower triangle of the symmetric matrix B, packed columnwise
	       in a linear array.  The j-th column of B is stored in the array BP as follows:  if
	       UPLO  =	'U',  BP(i  +  (j-1)*j/2)  =  B(i,j)  for  1<=i<=j; if UPLO = 'L', BP(i +
	       (j-1)*(2*n-j)/2) = B(i,j) for j<=i<=n.

	       On exit, the triangular factor U or L from the Cholesky factorization B	=  U**T*U
	       or B = L*L**T, in the same storage format as B.

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

       Z       (output) REAL array, dimension (LDZ, N)
	       If  JOBZ  =  'V',  then if INFO = 0, Z contains the matrix Z of eigenvectors.  The
	       eigenvectors are normalized as follows: if ITYPE = 1 or 2, Z**T*B*Z = I; if  ITYPE
	       = 3, Z**T*inv(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 >=
	       max(1,N).

       WORK    (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:  SPPTRF or SSPEV returned an error code:
	       <= N:  if INFO = i, SSPEV failed to converge; i off-diagonal elements of an inter-
	       mediate	tridiagonal form did not converge to zero.  > N:   if INFO = n + i, for 1
	       <= i <= n, then the leading minor of order i of B is not positive  definite.   The
	       factorization  of B could not be completed and no eigenvalues or eigenvectors were
	       computed.

LAPACK version 3.0			   15 June 2000 				 SSPGV(l)


All times are GMT -4. The time now is 11:01 PM.

Unix & Linux Forums Content Copyrightę1993-2018. All Rights Reserved.
×
UNIX.COM Login
Username:
Password:  
Show Password





Not a Forum Member?
Forgot Password?