802 lines
29 KiB
Fortran
802 lines
29 KiB
Fortran
c\BeginDoc
|
|
c
|
|
c\Name: znaup2
|
|
c
|
|
c\Description:
|
|
c Intermediate level interface called by znaupd .
|
|
c
|
|
c\Usage:
|
|
c call znaup2
|
|
c ( IDO, BMAT, N, WHICH, NEV, NP, TOL, RESID, MODE, IUPD,
|
|
c ISHIFT, MXITER, V, LDV, H, LDH, RITZ, BOUNDS,
|
|
c Q, LDQ, WORKL, IPNTR, WORKD, RWORK, INFO )
|
|
c
|
|
c\Arguments
|
|
c
|
|
c IDO, BMAT, N, WHICH, NEV, TOL, RESID: same as defined in znaupd .
|
|
c MODE, ISHIFT, MXITER: see the definition of IPARAM in znaupd .
|
|
c
|
|
c NP Integer. (INPUT/OUTPUT)
|
|
c Contains the number of implicit shifts to apply during
|
|
c each Arnoldi iteration.
|
|
c If ISHIFT=1, NP is adjusted dynamically at each iteration
|
|
c to accelerate convergence and prevent stagnation.
|
|
c This is also roughly equal to the number of matrix-vector
|
|
c products (involving the operator OP) per Arnoldi iteration.
|
|
c The logic for adjusting is contained within the current
|
|
c subroutine.
|
|
c If ISHIFT=0, NP is the number of shifts the user needs
|
|
c to provide via reverse comunication. 0 < NP < NCV-NEV.
|
|
c NP may be less than NCV-NEV since a leading block of the current
|
|
c upper Hessenberg matrix has split off and contains "unwanted"
|
|
c Ritz values.
|
|
c Upon termination of the IRA iteration, NP contains the number
|
|
c of "converged" wanted Ritz values.
|
|
c
|
|
c IUPD Integer. (INPUT)
|
|
c IUPD .EQ. 0: use explicit restart instead implicit update.
|
|
c IUPD .NE. 0: use implicit update.
|
|
c
|
|
c V Complex*16 N by (NEV+NP) array. (INPUT/OUTPUT)
|
|
c The Arnoldi basis vectors are returned in the first NEV
|
|
c columns of V.
|
|
c
|
|
c LDV Integer. (INPUT)
|
|
c Leading dimension of V exactly as declared in the calling
|
|
c program.
|
|
c
|
|
c H Complex*16 (NEV+NP) by (NEV+NP) array. (OUTPUT)
|
|
c H is used to store the generated upper Hessenberg matrix
|
|
c
|
|
c LDH Integer. (INPUT)
|
|
c Leading dimension of H exactly as declared in the calling
|
|
c program.
|
|
c
|
|
c RITZ Complex*16 array of length NEV+NP. (OUTPUT)
|
|
c RITZ(1:NEV) contains the computed Ritz values of OP.
|
|
c
|
|
c BOUNDS Complex*16 array of length NEV+NP. (OUTPUT)
|
|
c BOUNDS(1:NEV) contain the error bounds corresponding to
|
|
c the computed Ritz values.
|
|
c
|
|
c Q Complex*16 (NEV+NP) by (NEV+NP) array. (WORKSPACE)
|
|
c Private (replicated) work array used to accumulate the
|
|
c rotation in the shift application step.
|
|
c
|
|
c LDQ Integer. (INPUT)
|
|
c Leading dimension of Q exactly as declared in the calling
|
|
c program.
|
|
c
|
|
c WORKL Complex*16 work array of length at least
|
|
c (NEV+NP)**2 + 3*(NEV+NP). (WORKSPACE)
|
|
c Private (replicated) array on each PE or array allocated on
|
|
c the front end. It is used in shifts calculation, shifts
|
|
c application and convergence checking.
|
|
c
|
|
c
|
|
c IPNTR Integer array of length 3. (OUTPUT)
|
|
c Pointer to mark the starting locations in the WORKD for
|
|
c vectors used by the Arnoldi iteration.
|
|
c -------------------------------------------------------------
|
|
c IPNTR(1): pointer to the current operand vector X.
|
|
c IPNTR(2): pointer to the current result vector Y.
|
|
c IPNTR(3): pointer to the vector B * X when used in the
|
|
c shift-and-invert mode. X is the current operand.
|
|
c -------------------------------------------------------------
|
|
c
|
|
c WORKD Complex*16 work array of length 3*N. (WORKSPACE)
|
|
c Distributed array to be used in the basic Arnoldi iteration
|
|
c for reverse communication. The user should not use WORKD
|
|
c as temporary workspace during the iteration !!!!!!!!!!
|
|
c See Data Distribution Note in ZNAUPD .
|
|
c
|
|
c RWORK Double precision work array of length NEV+NP ( WORKSPACE)
|
|
c Private (replicated) array on each PE or array allocated on
|
|
c the front end.
|
|
c
|
|
c INFO Integer. (INPUT/OUTPUT)
|
|
c If INFO .EQ. 0, a randomly initial residual vector is used.
|
|
c If INFO .NE. 0, RESID contains the initial residual vector,
|
|
c possibly from a previous run.
|
|
c Error flag on output.
|
|
c = 0: Normal return.
|
|
c = 1: Maximum number of iterations taken.
|
|
c All possible eigenvalues of OP has been found.
|
|
c NP returns the number of converged Ritz values.
|
|
c = 2: No shifts could be applied.
|
|
c = -8: Error return from LAPACK eigenvalue calculation;
|
|
c This should never happen.
|
|
c = -9: Starting vector is zero.
|
|
c = -9999: Could not build an Arnoldi factorization.
|
|
c Size that was built in returned in NP.
|
|
c
|
|
c\EndDoc
|
|
c
|
|
c-----------------------------------------------------------------------
|
|
c
|
|
c\BeginLib
|
|
c
|
|
c\Local variables:
|
|
c xxxxxx Complex*16
|
|
c
|
|
c\References:
|
|
c 1. D.C. Sorensen, "Implicit Application of Polynomial Filters in
|
|
c a k-Step Arnoldi Method", SIAM J. Matr. Anal. Apps., 13 (1992),
|
|
c pp 357-385.
|
|
c 2. R.B. Lehoucq, "Analysis and Implementation of an Implicitly
|
|
c Restarted Arnoldi Iteration", Rice University Technical Report
|
|
c TR95-13, Department of Computational and Applied Mathematics.
|
|
c
|
|
c\Routines called:
|
|
c zgetv0 ARPACK initial vector generation routine.
|
|
c znaitr ARPACK Arnoldi factorization routine.
|
|
c znapps ARPACK application of implicit shifts routine.
|
|
c zneigh ARPACK compute Ritz values and error bounds routine.
|
|
c zngets ARPACK reorder Ritz values and error bounds routine.
|
|
c zsortc ARPACK sorting routine.
|
|
c ivout ARPACK utility routine that prints integers.
|
|
c second ARPACK utility routine for timing.
|
|
c zmout ARPACK utility routine that prints matrices
|
|
c zvout ARPACK utility routine that prints vectors.
|
|
c dvout ARPACK utility routine that prints vectors.
|
|
c dlamch LAPACK routine that determines machine constants.
|
|
c dlapy2 LAPACK routine to compute sqrt(x**2+y**2) carefully.
|
|
c zcopy Level 1 BLAS that copies one vector to another .
|
|
c zdotc Level 1 BLAS that computes the scalar product of two vectors.
|
|
c zswap Level 1 BLAS that swaps two vectors.
|
|
c dznrm2 Level 1 BLAS that computes the norm of a vector.
|
|
c
|
|
c\Author
|
|
c Danny Sorensen Phuong Vu
|
|
c Richard Lehoucq CRPC / Rice Universitya
|
|
c Chao Yang Houston, Texas
|
|
c Dept. of Computational &
|
|
c Applied Mathematics
|
|
c Rice University
|
|
c Houston, Texas
|
|
c
|
|
c\SCCS Information: @(#)
|
|
c FILE: naup2.F SID: 2.6 DATE OF SID: 06/01/00 RELEASE: 2
|
|
c
|
|
c\Remarks
|
|
c 1. None
|
|
c
|
|
c\EndLib
|
|
c
|
|
c-----------------------------------------------------------------------
|
|
c
|
|
subroutine znaup2
|
|
& ( ido, bmat, n, which, nev, np, tol, resid, mode, iupd,
|
|
& ishift, mxiter, v, ldv, h, ldh, ritz, bounds,
|
|
& q, ldq, workl, ipntr, workd, rwork, info )
|
|
c
|
|
c %----------------------------------------------------%
|
|
c | Include files for debugging and timing information |
|
|
c %----------------------------------------------------%
|
|
c
|
|
include 'debug.h'
|
|
include 'stat.h'
|
|
c
|
|
c %------------------%
|
|
c | Scalar Arguments |
|
|
c %------------------%
|
|
c
|
|
character bmat*1, which*2
|
|
integer ido, info, ishift, iupd, mode, ldh, ldq, ldv, mxiter,
|
|
& n, nev, np
|
|
Double precision
|
|
& tol
|
|
c
|
|
c %-----------------%
|
|
c | Array Arguments |
|
|
c %-----------------%
|
|
c
|
|
integer ipntr(13)
|
|
Complex*16
|
|
& bounds(nev+np), h(ldh,nev+np), q(ldq,nev+np),
|
|
& resid(n), ritz(nev+np), v(ldv,nev+np),
|
|
& workd(3*n), workl( (nev+np)*(nev+np+3) )
|
|
Double precision
|
|
& rwork(nev+np)
|
|
c
|
|
c %------------%
|
|
c | Parameters |
|
|
c %------------%
|
|
c
|
|
Complex*16
|
|
& one, zero
|
|
Double precision
|
|
& rzero
|
|
parameter (one = (1.0D+0, 0.0D+0) , zero = (0.0D+0, 0.0D+0) ,
|
|
& rzero = 0.0D+0 )
|
|
c
|
|
c %---------------%
|
|
c | Local Scalars |
|
|
c %---------------%
|
|
c
|
|
logical cnorm , getv0, initv , update, ushift
|
|
integer ierr , iter , kplusp, msglvl, nconv,
|
|
& nevbef, nev0 , np0 , nptemp, i ,
|
|
& j
|
|
Complex*16
|
|
& cmpnorm
|
|
Double precision
|
|
& rnorm , eps23, rtemp
|
|
character wprime*2
|
|
c
|
|
save cnorm, getv0, initv , update, ushift,
|
|
& rnorm, iter , kplusp, msglvl, nconv ,
|
|
& nevbef, nev0 , np0 , eps23
|
|
c
|
|
c
|
|
c %-----------------------%
|
|
c | Local array arguments |
|
|
c %-----------------------%
|
|
c
|
|
integer kp(3)
|
|
c
|
|
c %----------------------%
|
|
c | External Subroutines |
|
|
c %----------------------%
|
|
c
|
|
external zcopy , zgetv0 , znaitr , zneigh , zngets , znapps ,
|
|
& zsortc , zswap , zmout , zvout , ivout, second
|
|
c
|
|
c %--------------------%
|
|
c | External functions |
|
|
c %--------------------%
|
|
c
|
|
Complex*16
|
|
& zdotc
|
|
Double precision
|
|
& dznrm2 , dlamch , dlapy2
|
|
external zdotc , dznrm2 , dlamch , dlapy2
|
|
c
|
|
c %---------------------%
|
|
c | Intrinsic Functions |
|
|
c %---------------------%
|
|
c
|
|
intrinsic dimag , dble , min, max
|
|
c
|
|
c %-----------------------%
|
|
c | Executable Statements |
|
|
c %-----------------------%
|
|
c
|
|
if (ido .eq. 0) then
|
|
c
|
|
call second (t0)
|
|
c
|
|
msglvl = mcaup2
|
|
c
|
|
nev0 = nev
|
|
np0 = np
|
|
c
|
|
c %-------------------------------------%
|
|
c | kplusp is the bound on the largest |
|
|
c | Lanczos factorization built. |
|
|
c | nconv is the current number of |
|
|
c | "converged" eigenvalues. |
|
|
c | iter is the counter on the current |
|
|
c | iteration step. |
|
|
c %-------------------------------------%
|
|
c
|
|
kplusp = nev + np
|
|
nconv = 0
|
|
iter = 0
|
|
c
|
|
c %---------------------------------%
|
|
c | Get machine dependent constant. |
|
|
c %---------------------------------%
|
|
c
|
|
eps23 = dlamch ('Epsilon-Machine')
|
|
eps23 = eps23**(2.0D+0 / 3.0D+0 )
|
|
c
|
|
c %---------------------------------------%
|
|
c | Set flags for computing the first NEV |
|
|
c | steps of the Arnoldi factorization. |
|
|
c %---------------------------------------%
|
|
c
|
|
getv0 = .true.
|
|
update = .false.
|
|
ushift = .false.
|
|
cnorm = .false.
|
|
c
|
|
if (info .ne. 0) then
|
|
c
|
|
c %--------------------------------------------%
|
|
c | User provides the initial residual vector. |
|
|
c %--------------------------------------------%
|
|
c
|
|
initv = .true.
|
|
info = 0
|
|
else
|
|
initv = .false.
|
|
end if
|
|
end if
|
|
c
|
|
c %---------------------------------------------%
|
|
c | Get a possibly random starting vector and |
|
|
c | force it into the range of the operator OP. |
|
|
c %---------------------------------------------%
|
|
c
|
|
10 continue
|
|
c
|
|
if (getv0) then
|
|
call zgetv0 (ido, bmat, 1, initv, n, 1, v, ldv, resid, rnorm,
|
|
& ipntr, workd, info)
|
|
c
|
|
if (ido .ne. 99) go to 9000
|
|
c
|
|
if (rnorm .eq. rzero) then
|
|
c
|
|
c %-----------------------------------------%
|
|
c | The initial vector is zero. Error exit. |
|
|
c %-----------------------------------------%
|
|
c
|
|
info = -9
|
|
go to 1100
|
|
end if
|
|
getv0 = .false.
|
|
ido = 0
|
|
end if
|
|
c
|
|
c %-----------------------------------%
|
|
c | Back from reverse communication : |
|
|
c | continue with update step |
|
|
c %-----------------------------------%
|
|
c
|
|
if (update) go to 20
|
|
c
|
|
c %-------------------------------------------%
|
|
c | Back from computing user specified shifts |
|
|
c %-------------------------------------------%
|
|
c
|
|
if (ushift) go to 50
|
|
c
|
|
c %-------------------------------------%
|
|
c | Back from computing residual norm |
|
|
c | at the end of the current iteration |
|
|
c %-------------------------------------%
|
|
c
|
|
if (cnorm) go to 100
|
|
c
|
|
c %----------------------------------------------------------%
|
|
c | Compute the first NEV steps of the Arnoldi factorization |
|
|
c %----------------------------------------------------------%
|
|
c
|
|
call znaitr (ido, bmat, n, 0, nev, mode, resid, rnorm, v, ldv,
|
|
& h, ldh, ipntr, workd, info)
|
|
c
|
|
if (ido .ne. 99) go to 9000
|
|
c
|
|
if (info .gt. 0) then
|
|
np = info
|
|
mxiter = iter
|
|
info = -9999
|
|
go to 1200
|
|
end if
|
|
c
|
|
c %--------------------------------------------------------------%
|
|
c | |
|
|
c | M A I N ARNOLDI I T E R A T I O N L O O P |
|
|
c | Each iteration implicitly restarts the Arnoldi |
|
|
c | factorization in place. |
|
|
c | |
|
|
c %--------------------------------------------------------------%
|
|
c
|
|
1000 continue
|
|
c
|
|
iter = iter + 1
|
|
c
|
|
if (msglvl .gt. 0) then
|
|
call ivout (logfil, 1, iter, ndigit,
|
|
& '_naup2: **** Start of major iteration number ****')
|
|
end if
|
|
c
|
|
c %-----------------------------------------------------------%
|
|
c | Compute NP additional steps of the Arnoldi factorization. |
|
|
c | Adjust NP since NEV might have been updated by last call |
|
|
c | to the shift application routine znapps . |
|
|
c %-----------------------------------------------------------%
|
|
c
|
|
np = kplusp - nev
|
|
c
|
|
if (msglvl .gt. 1) then
|
|
call ivout (logfil, 1, nev, ndigit,
|
|
& '_naup2: The length of the current Arnoldi factorization')
|
|
call ivout (logfil, 1, np, ndigit,
|
|
& '_naup2: Extend the Arnoldi factorization by')
|
|
end if
|
|
c
|
|
c %-----------------------------------------------------------%
|
|
c | Compute NP additional steps of the Arnoldi factorization. |
|
|
c %-----------------------------------------------------------%
|
|
c
|
|
ido = 0
|
|
20 continue
|
|
update = .true.
|
|
c
|
|
call znaitr (ido, bmat, n, nev, np, mode, resid, rnorm,
|
|
& v , ldv , h, ldh, ipntr, workd, info)
|
|
c
|
|
if (ido .ne. 99) go to 9000
|
|
c
|
|
if (info .gt. 0) then
|
|
np = info
|
|
mxiter = iter
|
|
info = -9999
|
|
go to 1200
|
|
end if
|
|
update = .false.
|
|
c
|
|
if (msglvl .gt. 1) then
|
|
call dvout (logfil, 1, rnorm, ndigit,
|
|
& '_naup2: Corresponding B-norm of the residual')
|
|
end if
|
|
c
|
|
c %--------------------------------------------------------%
|
|
c | Compute the eigenvalues and corresponding error bounds |
|
|
c | of the current upper Hessenberg matrix. |
|
|
c %--------------------------------------------------------%
|
|
c
|
|
call zneigh (rnorm, kplusp, h, ldh, ritz, bounds,
|
|
& q, ldq, workl, rwork, ierr)
|
|
c
|
|
if (ierr .ne. 0) then
|
|
info = -8
|
|
go to 1200
|
|
end if
|
|
c
|
|
c %---------------------------------------------------%
|
|
c | Select the wanted Ritz values and their bounds |
|
|
c | to be used in the convergence test. |
|
|
c | The wanted part of the spectrum and corresponding |
|
|
c | error bounds are in the last NEV loc. of RITZ, |
|
|
c | and BOUNDS respectively. |
|
|
c %---------------------------------------------------%
|
|
c
|
|
nev = nev0
|
|
np = np0
|
|
c
|
|
c %--------------------------------------------------%
|
|
c | Make a copy of Ritz values and the corresponding |
|
|
c | Ritz estimates obtained from zneigh . |
|
|
c %--------------------------------------------------%
|
|
c
|
|
call zcopy (kplusp,ritz,1,workl(kplusp**2+1),1)
|
|
call zcopy (kplusp,bounds,1,workl(kplusp**2+kplusp+1),1)
|
|
c
|
|
c %---------------------------------------------------%
|
|
c | Select the wanted Ritz values and their bounds |
|
|
c | to be used in the convergence test. |
|
|
c | The wanted part of the spectrum and corresponding |
|
|
c | bounds are in the last NEV loc. of RITZ |
|
|
c | BOUNDS respectively. |
|
|
c %---------------------------------------------------%
|
|
c
|
|
call zngets (ishift, which, nev, np, ritz, bounds)
|
|
c
|
|
c %------------------------------------------------------------%
|
|
c | Convergence test: currently we use the following criteria. |
|
|
c | The relative accuracy of a Ritz value is considered |
|
|
c | acceptable if: |
|
|
c | |
|
|
c | error_bounds(i) .le. tol*max(eps23, magnitude_of_ritz(i)). |
|
|
c | |
|
|
c %------------------------------------------------------------%
|
|
c
|
|
nconv = 0
|
|
c
|
|
do 25 i = 1, nev
|
|
rtemp = max( eps23, dlapy2 ( dble (ritz(np+i)),
|
|
& dimag (ritz(np+i)) ) )
|
|
if ( dlapy2 (dble (bounds(np+i)),dimag (bounds(np+i)))
|
|
& .le. tol*rtemp ) then
|
|
nconv = nconv + 1
|
|
end if
|
|
25 continue
|
|
c
|
|
if (msglvl .gt. 2) then
|
|
kp(1) = nev
|
|
kp(2) = np
|
|
kp(3) = nconv
|
|
call ivout (logfil, 3, kp, ndigit,
|
|
& '_naup2: NEV, NP, NCONV are')
|
|
call zvout (logfil, kplusp, ritz, ndigit,
|
|
& '_naup2: The eigenvalues of H')
|
|
call zvout (logfil, kplusp, bounds, ndigit,
|
|
& '_naup2: Ritz estimates of the current NCV Ritz values')
|
|
end if
|
|
c
|
|
c %---------------------------------------------------------%
|
|
c | Count the number of unwanted Ritz values that have zero |
|
|
c | Ritz estimates. If any Ritz estimates are equal to zero |
|
|
c | then a leading block of H of order equal to at least |
|
|
c | the number of Ritz values with zero Ritz estimates has |
|
|
c | split off. None of these Ritz values may be removed by |
|
|
c | shifting. Decrease NP the number of shifts to apply. If |
|
|
c | no shifts may be applied, then prepare to exit |
|
|
c %---------------------------------------------------------%
|
|
c
|
|
nptemp = np
|
|
do 30 j=1, nptemp
|
|
if (bounds(j) .eq. zero) then
|
|
np = np - 1
|
|
nev = nev + 1
|
|
end if
|
|
30 continue
|
|
c
|
|
if ( (nconv .ge. nev0) .or.
|
|
& (iter .gt. mxiter) .or.
|
|
& (np .eq. 0) ) then
|
|
c
|
|
if (msglvl .gt. 4) then
|
|
call zvout (logfil, kplusp, workl(kplusp**2+1), ndigit,
|
|
& '_naup2: Eigenvalues computed by _neigh:')
|
|
call zvout (logfil, kplusp, workl(kplusp**2+kplusp+1),
|
|
& ndigit,
|
|
& '_naup2: Ritz estimates computed by _neigh:')
|
|
end if
|
|
c
|
|
c %------------------------------------------------%
|
|
c | Prepare to exit. Put the converged Ritz values |
|
|
c | and corresponding bounds in RITZ(1:NCONV) and |
|
|
c | BOUNDS(1:NCONV) respectively. Then sort. Be |
|
|
c | careful when NCONV > NP |
|
|
c %------------------------------------------------%
|
|
c
|
|
c %------------------------------------------%
|
|
c | Use h( 3,1 ) as storage to communicate |
|
|
c | rnorm to zneupd if needed |
|
|
c %------------------------------------------%
|
|
|
|
h(3,1) = dcmplx (rnorm,rzero)
|
|
c
|
|
c %----------------------------------------------%
|
|
c | Sort Ritz values so that converged Ritz |
|
|
c | values appear within the first NEV locations |
|
|
c | of ritz and bounds, and the most desired one |
|
|
c | appears at the front. |
|
|
c %----------------------------------------------%
|
|
c
|
|
if (which .eq. 'LM') wprime = 'SM'
|
|
if (which .eq. 'SM') wprime = 'LM'
|
|
if (which .eq. 'LR') wprime = 'SR'
|
|
if (which .eq. 'SR') wprime = 'LR'
|
|
if (which .eq. 'LI') wprime = 'SI'
|
|
if (which .eq. 'SI') wprime = 'LI'
|
|
c
|
|
call zsortc (wprime, .true., kplusp, ritz, bounds)
|
|
c
|
|
c %--------------------------------------------------%
|
|
c | Scale the Ritz estimate of each Ritz value |
|
|
c | by 1 / max(eps23, magnitude of the Ritz value). |
|
|
c %--------------------------------------------------%
|
|
c
|
|
do 35 j = 1, nev0
|
|
rtemp = max( eps23, dlapy2 ( dble (ritz(j)),
|
|
& dimag (ritz(j)) ) )
|
|
bounds(j) = bounds(j)/rtemp
|
|
35 continue
|
|
c
|
|
c %---------------------------------------------------%
|
|
c | Sort the Ritz values according to the scaled Ritz |
|
|
c | estimates. This will push all the converged ones |
|
|
c | towards the front of ritz, bounds (in the case |
|
|
c | when NCONV < NEV.) |
|
|
c %---------------------------------------------------%
|
|
c
|
|
wprime = 'LM'
|
|
call zsortc (wprime, .true., nev0, bounds, ritz)
|
|
c
|
|
c %----------------------------------------------%
|
|
c | Scale the Ritz estimate back to its original |
|
|
c | value. |
|
|
c %----------------------------------------------%
|
|
c
|
|
do 40 j = 1, nev0
|
|
rtemp = max( eps23, dlapy2 ( dble (ritz(j)),
|
|
& dimag (ritz(j)) ) )
|
|
bounds(j) = bounds(j)*rtemp
|
|
40 continue
|
|
c
|
|
c %-----------------------------------------------%
|
|
c | Sort the converged Ritz values again so that |
|
|
c | the "threshold" value appears at the front of |
|
|
c | ritz and bound. |
|
|
c %-----------------------------------------------%
|
|
c
|
|
call zsortc (which, .true., nconv, ritz, bounds)
|
|
c
|
|
if (msglvl .gt. 1) then
|
|
call zvout (logfil, kplusp, ritz, ndigit,
|
|
& '_naup2: Sorted eigenvalues')
|
|
call zvout (logfil, kplusp, bounds, ndigit,
|
|
& '_naup2: Sorted ritz estimates.')
|
|
end if
|
|
c
|
|
c %------------------------------------%
|
|
c | Max iterations have been exceeded. |
|
|
c %------------------------------------%
|
|
c
|
|
if (iter .gt. mxiter .and. nconv .lt. nev0) info = 1
|
|
c
|
|
c %---------------------%
|
|
c | No shifts to apply. |
|
|
c %---------------------%
|
|
c
|
|
if (np .eq. 0 .and. nconv .lt. nev0) info = 2
|
|
c
|
|
np = nconv
|
|
go to 1100
|
|
c
|
|
else if ( (nconv .lt. nev0) .and. (ishift .eq. 1) ) then
|
|
c
|
|
c %-------------------------------------------------%
|
|
c | Do not have all the requested eigenvalues yet. |
|
|
c | To prevent possible stagnation, adjust the size |
|
|
c | of NEV. |
|
|
c %-------------------------------------------------%
|
|
c
|
|
nevbef = nev
|
|
nev = nev + min(nconv, np/2)
|
|
if (nev .eq. 1 .and. kplusp .ge. 6) then
|
|
nev = kplusp / 2
|
|
else if (nev .eq. 1 .and. kplusp .gt. 3) then
|
|
nev = 2
|
|
end if
|
|
np = kplusp - nev
|
|
c
|
|
c %---------------------------------------%
|
|
c | If the size of NEV was just increased |
|
|
c | resort the eigenvalues. |
|
|
c %---------------------------------------%
|
|
c
|
|
if (nevbef .lt. nev)
|
|
& call zngets (ishift, which, nev, np, ritz, bounds)
|
|
c
|
|
end if
|
|
c
|
|
if (msglvl .gt. 0) then
|
|
call ivout (logfil, 1, nconv, ndigit,
|
|
& '_naup2: no. of "converged" Ritz values at this iter.')
|
|
if (msglvl .gt. 1) then
|
|
kp(1) = nev
|
|
kp(2) = np
|
|
call ivout (logfil, 2, kp, ndigit,
|
|
& '_naup2: NEV and NP are')
|
|
call zvout (logfil, nev, ritz(np+1), ndigit,
|
|
& '_naup2: "wanted" Ritz values ')
|
|
call zvout (logfil, nev, bounds(np+1), ndigit,
|
|
& '_naup2: Ritz estimates of the "wanted" values ')
|
|
end if
|
|
end if
|
|
c
|
|
if (ishift .eq. 0) then
|
|
c
|
|
c %-------------------------------------------------------%
|
|
c | User specified shifts: pop back out to get the shifts |
|
|
c | and return them in the first 2*NP locations of WORKL. |
|
|
c %-------------------------------------------------------%
|
|
c
|
|
ushift = .true.
|
|
ido = 3
|
|
go to 9000
|
|
end if
|
|
50 continue
|
|
ushift = .false.
|
|
c
|
|
if ( ishift .ne. 1 ) then
|
|
c
|
|
c %----------------------------------%
|
|
c | Move the NP shifts from WORKL to |
|
|
c | RITZ, to free up WORKL |
|
|
c | for non-exact shift case. |
|
|
c %----------------------------------%
|
|
c
|
|
call zcopy (np, workl, 1, ritz, 1)
|
|
end if
|
|
c
|
|
if (msglvl .gt. 2) then
|
|
call ivout (logfil, 1, np, ndigit,
|
|
& '_naup2: The number of shifts to apply ')
|
|
call zvout (logfil, np, ritz, ndigit,
|
|
& '_naup2: values of the shifts')
|
|
if ( ishift .eq. 1 )
|
|
& call zvout (logfil, np, bounds, ndigit,
|
|
& '_naup2: Ritz estimates of the shifts')
|
|
end if
|
|
c
|
|
c %---------------------------------------------------------%
|
|
c | Apply the NP implicit shifts by QR bulge chasing. |
|
|
c | Each shift is applied to the whole upper Hessenberg |
|
|
c | matrix H. |
|
|
c | The first 2*N locations of WORKD are used as workspace. |
|
|
c %---------------------------------------------------------%
|
|
c
|
|
call znapps (n, nev, np, ritz, v, ldv,
|
|
& h, ldh, resid, q, ldq, workl, workd)
|
|
c
|
|
c %---------------------------------------------%
|
|
c | Compute the B-norm of the updated residual. |
|
|
c | Keep B*RESID in WORKD(1:N) to be used in |
|
|
c | the first step of the next call to znaitr . |
|
|
c %---------------------------------------------%
|
|
c
|
|
cnorm = .true.
|
|
call second (t2)
|
|
if (bmat .eq. 'G') then
|
|
nbx = nbx + 1
|
|
call zcopy (n, resid, 1, workd(n+1), 1)
|
|
ipntr(1) = n + 1
|
|
ipntr(2) = 1
|
|
ido = 2
|
|
c
|
|
c %----------------------------------%
|
|
c | Exit in order to compute B*RESID |
|
|
c %----------------------------------%
|
|
c
|
|
go to 9000
|
|
else if (bmat .eq. 'I') then
|
|
call zcopy (n, resid, 1, workd, 1)
|
|
end if
|
|
c
|
|
100 continue
|
|
c
|
|
c %----------------------------------%
|
|
c | Back from reverse communication; |
|
|
c | WORKD(1:N) := B*RESID |
|
|
c %----------------------------------%
|
|
c
|
|
if (bmat .eq. 'G') then
|
|
call second (t3)
|
|
tmvbx = tmvbx + (t3 - t2)
|
|
end if
|
|
c
|
|
if (bmat .eq. 'G') then
|
|
cmpnorm = zdotc (n, resid, 1, workd, 1)
|
|
rnorm = sqrt(dlapy2 (dble (cmpnorm),dimag (cmpnorm)))
|
|
else if (bmat .eq. 'I') then
|
|
rnorm = dznrm2 (n, resid, 1)
|
|
end if
|
|
cnorm = .false.
|
|
c
|
|
if (msglvl .gt. 2) then
|
|
call dvout (logfil, 1, rnorm, ndigit,
|
|
& '_naup2: B-norm of residual for compressed factorization')
|
|
call zmout (logfil, nev, nev, h, ldh, ndigit,
|
|
& '_naup2: Compressed upper Hessenberg matrix H')
|
|
end if
|
|
c
|
|
go to 1000
|
|
c
|
|
c %---------------------------------------------------------------%
|
|
c | |
|
|
c | E N D O F M A I N I T E R A T I O N L O O P |
|
|
c | |
|
|
c %---------------------------------------------------------------%
|
|
c
|
|
1100 continue
|
|
c
|
|
mxiter = iter
|
|
nev = nconv
|
|
c
|
|
1200 continue
|
|
ido = 99
|
|
c
|
|
c %------------%
|
|
c | Error Exit |
|
|
c %------------%
|
|
c
|
|
call second (t1)
|
|
tcaup2 = t1 - t0
|
|
c
|
|
9000 continue
|
|
c
|
|
c %---------------%
|
|
c | End of znaup2 |
|
|
c %---------------%
|
|
c
|
|
return
|
|
end
|