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Fixed a small bug in the bfgs algorithm: the memory of the last successeful 

was lost lost in the case of a history reset.
C.S.


git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@2880 c92efa57-630b-4861-b058-cf58834340f0
This commit is contained in:
sbraccia 2006-03-08 02:04:08 +00:00
parent 4ed1de1add
commit 9e122fce5c
1 changed files with 43 additions and 41 deletions
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84
Modules/bfgs_module.f90
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@ -1,5 +1,5 @@
!
! Copyright (C) 2003-2005 Quantum-ESPRESSO group
! Copyright (C) 2003-2006 Quantum-ESPRESSO group
! This file is distributed under the terms of the
! GNU General Public License. See the file `License'
! in the root directory of the present distribution,
@ -151,11 +151,11 @@ MODULE bfgs_module
!
IF ( .NOT. ALLOCATED( inv_hess ) ) ALLOCATE( inv_hess( dim, dim ) )
!
IF ( .NOT. ALLOCATED( pos_p ) ) ALLOCATE( pos_p( dim ) )
IF ( .NOT. ALLOCATED( grad_p ) ) ALLOCATE( grad_p( dim ) )
IF ( .NOT. ALLOCATED( step ) ) ALLOCATE( step( dim ) )
IF ( .NOT. ALLOCATED( step_old ) ) ALLOCATE( step_old( dim ) )
IF ( .NOT. ALLOCATED( pos_best ) ) ALLOCATE( pos_best( dim ) )
IF ( .NOT. ALLOCATED( pos_p ) ) ALLOCATE( pos_p( dim ) )
IF ( .NOT. ALLOCATED( grad_p ) ) ALLOCATE( grad_p( dim ) )
IF ( .NOT. ALLOCATED( step ) ) ALLOCATE( step( dim ) )
IF ( .NOT. ALLOCATED( step_old ) ) ALLOCATE( step_old( dim ) )
IF ( .NOT. ALLOCATED( pos_best ) ) ALLOCATE( pos_best( dim ) )
!
! ... the BFGS file is read
!
@ -206,7 +206,7 @@ MODULE bfgs_module
!
! ... s_min = - 0.5 * ( dE(0)*s'*s' ) / ( E(s') - E(0) - dE(0)*s' )
!
dE0s = ( grad_p(:) .dot. step_old )
dE0s = ( grad_p(:) .dot. step_old(:) )
!
den = energy - energy_p - dE0s
!
@ -226,10 +226,18 @@ MODULE bfgs_module
& FMT = '(5X,"new trust radius",T30,"= ",F18.10," bohr")' ) &
trust_radius
!
! ... values from the last succeseful bfgs step are restored
!
pos(:) = pos_p(:)
energy = energy_p
grad(:) = grad_p(:)
!
IF ( trust_radius < trust_radius_min ) THEN
!
! ... the history is reset
!
!
WRITE( UNIT = stdout, &
FMT = '(/,5X,"trust_radius < trust_radius_min")' )
WRITE( UNIT = stdout, FMT = '(/,5X,"resetting bfgs history",/)' )
!
IF ( trust_radius_old == trust_radius_min ) THEN
@ -237,28 +245,22 @@ MODULE bfgs_module
! ... the history has already been reset at the previous step :
! ... something is going wrong
!
WRITE( UNIT = stdout, FMT = '(5X,"Notice: bfgs history", &
& " already reset at previous step",/)' )
CALL errore( 'bfgs', &
'bfgs history already reset at previous step', 1 )
!
END IF
!
inv_hess = identity( dim )
inv_hess(:,:) = identity( dim )
!
step = - grad
step(:) = - grad(:)
!
trust_radius = trust_radius_min
!
ELSE
!
! ... values from the last succeseful bfgs step are restored
!
pos = pos_p
energy = energy_p
grad = grad_p
!
! ... old bfgs direction ( normalized ) is recovered
!
step = step_old / trust_radius_old
step(:) = step_old(:) / trust_radius_old
!
END IF
!
@ -327,8 +329,8 @@ MODULE bfgs_module
CALL DGEMM( 'T', 'N', k, k, dim, 1.D0, res, &
dim, res, dim, 0.D0, overlap, k_m )
!
overlap( :, k_m ) = 1.D0
overlap( k_m, k_m ) = 0.D0
overlap(:, k_m) = 1.D0
overlap(k_m,k_m) = 0.D0
!
! ... overlap is inverted
!
@ -343,31 +345,31 @@ MODULE bfgs_module
!
END FORALL
!
work = (/ ( 0.D0, i = 1, k ), 1.D0 /)
work(:) = (/ ( 0.D0, i = 1, k ), 1.D0 /)
!
pos_best = 0.D0
step = 0.D0
pos_best(:) = 0.D0
step(:) = 0.D0
!
DO i = 1, k
!
gamma0 = SUM( overlap(:,i) * work(:) )
!
pos_best = pos_best + gamma0 * pos_old(:,i)
pos_best(:) = pos_best(:) + gamma0 * pos_old(:,i)
!
step = step - gamma0 * res(:,i)
step(:) = step(:) - gamma0 * res(:,i)
!
END DO
!
! ... the step must be consistent with the old positions
!
step = step + ( pos_best - pos )
step(:) = step(:) + ( pos_best(:) - pos(:) )
!
IF ( ( grad .dot. step ) > 0.D0 ) THEN
IF ( ( grad(:) .dot. step(:) ) > 0.D0 ) THEN
!
! ... if the extrapolated direction is uphill the last
! ... gradient only is uded
!
step = - ( inv_hess .times. grad )
step(:) = - ( inv_hess(:,:) .times. grad(:) )
!
END IF
!
@ -375,7 +377,7 @@ MODULE bfgs_module
!
ELSE
!
step = - ( inv_hess .times. grad )
step(:) = - ( inv_hess(:,:) .times. grad(:) )
!
END IF
!
@ -390,14 +392,14 @@ MODULE bfgs_module
!
END IF
!
IF ( ( grad .dot. step ) > 0.D0 ) THEN
IF ( ( grad(:) .dot. step(:) ) > 0.D0 ) THEN
!
WRITE( UNIT = stdout, &
FMT = '(5X,"uphill step: resetting bfgs history",/)' )
!
step = - grad
step(:) = - grad(:)
!
inv_hess = identity( dim )
inv_hess(:,:) = identity( dim )
!
END IF
!
@ -425,17 +427,17 @@ MODULE bfgs_module
!
! ... step along the bfgs direction
!
IF ( norm( step ) < eps16 ) THEN
IF ( norm( step(:) ) < eps16 ) THEN
!
WRITE( UNIT = stdout, &
& FMT = '(5X,"WARNING : norm( step )",T30,"= ",F18.10)' ) &
norm( step )
norm( step(:) )
!
step = - grad
step(:) = - grad(:)
!
ELSE
!
step = trust_radius * step / norm( step )
step(:) = trust_radius * step(:) / norm( step(:) )
!
END IF
!
@ -446,7 +448,7 @@ MODULE bfgs_module
!
! ... positions are updated
!
pos = pos + step
pos(:) = pos(:) + step(:)
!
END SUBROUTINE bfgs
!
@ -605,9 +607,9 @@ MODULE bfgs_module
!
! ... the history is reset
!
WRITE( stdout, '(/,5X,"WARINIG: unexpected behaviour in ", &
& "update_inverse_hessian")' )
WRITE( stdout, '(5X," resetting bfgs history",/)' )
WRITE( stdout, '(/,5X,"WARINIG: unexpected ", &
& "behaviour in update_inverse_hessian")' )
WRITE( stdout, '( 5X," resetting bfgs history",/)' )
!
inv_hess = identity( dim )
!