zhpgst.f man page

zhpgst.f —

Synopsis

Functions/Subroutines

subroutine zhpgst (ITYPE, UPLO, N, AP, BP, INFO)
ZHPGST

Function/Subroutine Documentation

subroutine zhpgst (integer ITYPE, character UPLO, integer N, complex*16, dimension( * ) AP, complex*16, dimension( * ) BP, integer INFO)

ZHPGST  

Purpose:

 ZHPGST reduces a complex Hermitian-definite generalized
 eigenproblem to standard form, using packed storage.

 If ITYPE = 1, the problem is A*x = lambda*B*x,
 and A is overwritten by inv(U**H)*A*inv(U) or inv(L)*A*inv(L**H)

 If ITYPE = 2 or 3, the problem is A*B*x = lambda*x or
 B*A*x = lambda*x, and A is overwritten by U*A*U**H or L**H*A*L.

 B must have been previously factorized as U**H*U or L*L**H by ZPPTRF.
Parameters:

ITYPE

          ITYPE is INTEGER
          = 1: compute inv(U**H)*A*inv(U) or inv(L)*A*inv(L**H);
          = 2 or 3: compute U*A*U**H or L**H*A*L.

UPLO

          UPLO is CHARACTER*1
          = 'U':  Upper triangle of A is stored and B is factored as
                  U**H*U;
          = 'L':  Lower triangle of A is stored and B is factored as
                  L*L**H.

N

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

AP

          AP is COMPLEX*16 array, dimension (N*(N+1)/2)
          On entry, the upper or lower triangle of the Hermitian 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)*(2n-j)/2) = A(i,j) for j<=i<=n.

          On exit, if INFO = 0, the transformed matrix, stored in the
          same format as A.

BP

          BP is COMPLEX*16 array, dimension (N*(N+1)/2)
          The triangular factor from the Cholesky factorization of B,
          stored in the same format as A, as returned by ZPPTRF.

INFO

          INFO is INTEGER
          = 0:  successful exit
          < 0:  if INFO = -i, the i-th argument had an illegal value
Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

December 2016

Definition at line 115 of file zhpgst.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

The man page zhpgst(3) is an alias of zhpgst.f(3).

Sat Jun 24 2017 Version 3.7.1 LAPACK