centos man page for dspgv

dspgv.f(3)							      LAPACK								dspgv.f(3)

NAME
       dspgv.f -

SYNOPSIS
   Functions/Subroutines
       subroutine dspgv (ITYPE, JOBZ, UPLO, N, AP, BP, W, Z, LDZ, WORK, INFO)
	   DSPGST

Function/Subroutine Documentation
   subroutine dspgv (integerITYPE, characterJOBZ, characterUPLO, integerN, double precision, dimension( * )AP, double precision, dimension( * )BP,
       double precision, dimension( * )W, double precision, dimension( ldz, * )Z, integerLDZ, double precision, dimension( * )WORK, integerINFO)
       DSPGST

       Purpose:

	    DSPGV 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.

       Parameters:
	   ITYPE

		     ITYPE is 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

		     JOBZ is CHARACTER*1
		     = 'N':  Compute eigenvalues only;
		     = 'V':  Compute eigenvalues and eigenvectors.

	   UPLO

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

	   N

		     N is INTEGER
		     The order of the matrices A and B.  N >= 0.

	   AP

		     AP is DOUBLE PRECISION 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

		     BP is DOUBLE PRECISION 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

		     W is DOUBLE PRECISION array, dimension (N)
		     If INFO = 0, the eigenvalues in ascending order.

	   Z

		     Z is DOUBLE PRECISION 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

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

	   WORK

		     WORK is DOUBLE PRECISION array, dimension (3*N)

	   INFO

		     INFO is INTEGER
		     = 0:  successful exit
		     < 0:  if INFO = -i, the i-th argument had an illegal value
		     > 0:  DPPTRF or DSPEV returned an error code:
			<= N:  if INFO = i, DSPEV 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 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.

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   November 2011

       Definition at line 161 of file dspgv.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2							  Tue Sep 25 2012							dspgv.f(3)