! E05SAF Example Program Text
! Mark 30.2 Release. NAG Copyright 2024.
Module e05safe_mod
! E05SAF Example Program Module:
! Parameters and User-defined Routines
! .. Use Statements ..
Use nag_library, Only: nag_wp
! .. Implicit None Statement ..
Implicit None
! .. Accessibility Statements ..
Private
Public :: display_option, display_result, &
monmod, objfun_schwefel
! .. Parameters ..
Real (Kind=nag_wp), Parameter, Public :: f_target = &
-837.9657745448674_nag_wp
Integer, Parameter :: detail_level = 0, report_freq = 100
Integer, Parameter, Public :: liopts = 100, liuser = 1, &
lopts = 100, lruser = 1, ndim = 2, &
nout = 6
Real (Kind=nag_wp), Parameter :: x_target(ndim) = &
-420.9687463599820_nag_wp
Contains
Subroutine objfun_schwefel(mode,ndim,x,objf,vecout,nstate,iuser,ruser)
! Objfun routine for the Schwefel function for E05SAF.
! .. Scalar Arguments ..
Real (Kind=nag_wp), Intent (Inout) :: objf
Integer, Intent (Inout) :: mode
Integer, Intent (In) :: ndim, nstate
! .. Array Arguments ..
Real (Kind=nag_wp), Intent (Inout) :: ruser(*), vecout(ndim)
Real (Kind=nag_wp), Intent (In) :: x(ndim)
Integer, Intent (Inout) :: iuser(*)
! .. Local Scalars ..
Logical :: evalobjf, evalobjg
! .. Intrinsic Procedures ..
Intrinsic :: abs, cos, sin, sqrt, sum
! .. Executable Statements ..
! Test NSTATE to indicate what stage of computation has been reached.
Select Case (nstate)
Case (2)
! OBJFUN is called for the very first time.
Case (1)
! OBJFUN is called on entry to a NAG local minimizer.
Case Default
! This will be the normal value of NSTATE.
End Select
! Test MODE to determine whether to calculate OBJF and/or OBJGRD.
evalobjf = .False.
evalobjg = .False.
Select Case (mode)
Case (0,5)
! Only the value of the objective function is needed.
evalobjf = .True.
Case (1,6)
! Only the values of the NDIM gradients are required.
evalobjg = .True.
Case (2,7)
! Both the objective function and the NDIM gradients are required.
evalobjf = .True.
evalobjg = .True.
End Select
If (evalobjf) Then
! Evaluate the objective function.
objf = sum(x(1:ndim)*sin(sqrt(abs(x(1:ndim)))))
End If
If (evalobjg) Then
! Calculate the gradient of the objective function,
! and return the result in VECOUT.
vecout = sqrt(abs(x))
vecout = sin(vecout) + 0.5E0_nag_wp*vecout*cos(vecout)
End If
Return
End Subroutine objfun_schwefel
Subroutine monmod(ndim,npar,x,xb,fb,xbest,fbest,itt,iuser,ruser,inform)
! .. Scalar Arguments ..
Real (Kind=nag_wp), Intent (In) :: fb
Integer, Intent (Inout) :: inform
Integer, Intent (In) :: ndim, npar
! .. Array Arguments ..
Real (Kind=nag_wp), Intent (In) :: fbest(npar), xb(ndim), &
xbest(ndim,npar)
Real (Kind=nag_wp), Intent (Inout) :: ruser(*), x(ndim,npar)
Integer, Intent (In) :: itt(6)
Integer, Intent (Inout) :: iuser(*)
! .. Local Scalars ..
Integer :: indent, j
! .. Intrinsic Procedures ..
Intrinsic :: modulo, repeat
! .. Executable Statements ..
If (detail_level>=2) Then
! Report on the first iteration, and every report_freq iterations.
If (itt(1)==1 .Or. modulo(itt(1),report_freq)==0) Then
Write (nout,*) '* Locations of particles'
indent = 2
Do j = 1, npar
Write (nout,99999) repeat(' ',indent), j
Write (nout,99998) repeat(' ',indent), x(1:ndim,j)
End Do
Write (nout,*) '* Cognitive memory'
Do j = 1, npar
Write (nout,99999) repeat(' ',indent), j
Write (nout,*) repeat(' ',indent*2), '* Best position'
Write (nout,99998) repeat(' ',indent*2), xbest(1:ndim,j)
Write (nout,*) repeat(' ',indent*2), &
'* Function value at best position'
Write (nout,99997) repeat(' ',indent*2), fbest(j)
End Do
Write (nout,*) '* Current global optimum candidate'
Write (nout,99998) repeat(' ',indent), xb(1:ndim)
Write (nout,*) '* Current global optimum value'
Write (nout,99997) repeat(' ',indent), fb
End If
End If
! If required set INFORM<0 to force exit
inform = 0
Flush (nout)
Return
99999 Format (1X,A,'* Particle ',I3)
99998 Format (1X,A,(6F13.5))
99997 Format (1X,A,F13.5)
End Subroutine monmod
Subroutine display_option(optstr,optype,ivalue,rvalue,cvalue)
! Subroutine to query optype and print the appropriate option values
! .. Scalar Arguments ..
Real (Kind=nag_wp), Intent (In) :: rvalue
Integer, Intent (In) :: ivalue, optype
Character (*), Intent (In) :: cvalue, optstr
! .. Executable Statements ..
Select Case (optype)
Case (1)
Write (nout,99999) optstr, ivalue
Case (2)
Write (nout,99998) optstr, rvalue
Case (3)
Write (nout,99997) optstr, cvalue
Case (4)
Write (nout,99996) optstr, ivalue, cvalue
Case (5)
Write (nout,99995) optstr, rvalue, cvalue
Case Default
End Select
Flush (nout)
Return
99999 Format (3X,A36,' : ',I13)
99998 Format (3X,A36,' : ',F13.4)
99997 Format (3X,A36,' : ',16X,A16)
99996 Format (3X,A36,' : ',I13,3X,A16)
99995 Format (3X,A36,' : ',F13.4,3X,A16)
End Subroutine display_option
Subroutine display_result(ndim,xb,fb,itt,inform)
! Display final results in comparison to known global optimum.
! .. Use Statements ..
Use nag_library, Only: x04cbf
! .. Parameters ..
Integer, Parameter :: indent = 1, ncols = 79
Character (10), Parameter :: clabs(1:2) = (/'x_target ', &
'xb '/)
Character (1), Parameter :: diag = 'N', labcol = 'C', &
labrow = 'I', matrix = 'G'
Character (5), Parameter :: form = 'F12.2'
! .. Scalar Arguments ..
Real (Kind=nag_wp), Intent (In) :: fb
Integer, Intent (In) :: inform, ndim
! .. Array Arguments ..
Real (Kind=nag_wp), Intent (In) :: xb(ndim)
Integer, Intent (In) :: itt(6)
! .. Local Scalars ..
Integer :: ifail, ldxcom
Character (ncols) :: title
! .. Local Arrays ..
Real (Kind=nag_wp), Allocatable :: xcom(:,:)
! .. Executable Statements ..
! Display final counters.
Write (nout,*) ' Algorithm Statistics'
Write (nout,*) ' --------------------'
Write (nout,99997) 'Total complete iterations : ', itt(1)
Write (nout,99997) 'Complete iterations since improvement : ', itt(2)
Write (nout,99997) 'Total particles converged to xb : ', itt(3)
Write (nout,99997) 'Total improvements to global optimum : ', itt(4)
Write (nout,99997) 'Total function evaluations : ', itt(5)
Write (nout,99997) 'Total particles re-initialized : ', itt(6)
! Display why finalization occurred.
Write (nout,*)
Select Case (inform)
Case (1)
Write (nout,99996) 'Target value achieved'
Case (2)
Write (nout,99996) 'Minimum swarm standard deviation obtained'
Case (3)
Write (nout,99996) 'Sufficient particles converged'
Case (4)
Write (nout,99996) 'Maximum static iterations attained'
Case (5)
Write (nout,99996) 'Maximum complete iterations attained'
Case (6)
Write (nout,99996) 'Maximum function evaluations exceeded'
Case (:-1)
Write (nout,99995) inform
Case Default
End Select
! Display final objective value and location.
Write (nout,*)
Write (nout,99999) f_target
Write (nout,99998) fb
ldxcom = ndim
Allocate (xcom(ldxcom,2))
xcom(1:ndim,1) = x_target(1:ndim)
xcom(1:ndim,2) = xb(1:ndim)
Write (nout,*)
Flush (nout)
title = 'Comparison between known and achieved optima.'
ifail = 0
Call x04cbf(matrix,diag,ndim,2,xcom,ldxcom,form,title,labrow,clabs, &
labcol,clabs,ncols,indent,ifail)
Deallocate (xcom)
Write (nout,*)
Return
99999 Format (' Known objective optimum ',13X,' : ',F13.5)
99998 Format (' Achieved objective value',13X,' : ',F13.5)
99997 Format (2X,A40,I13)
99996 Format (2X,'Solution Status : ',A43)
99995 Format (' User termination case :',I16)
End Subroutine display_result
End Module e05safe_mod
Program e05safe
! E05SAF Example Main Program
! This example program demonstrates how to use E05SAF in standard
! execution, and with a selection of coupled local minimizers.
! The non-default option 'REPEATABILITY ON' is used here, giving
! repeatable results.
! .. Use Statements ..
Use e05safe_mod, Only: display_option, display_result, f_target, liopts, &
liuser, lopts, lruser, monmod, ndim, nout, &
objfun_schwefel
Use nag_library, Only: e05saf, e05zkf, e05zlf, nag_wp, x06acf
! .. Implicit None Statement ..
Implicit None
! .. Local Scalars ..
Real (Kind=nag_wp) :: fb, rvalue
Integer :: ifail, inform, ivalue, npar, optype
Character (16) :: cvalue
Character (80) :: optstr
! .. Local Arrays ..
Real (Kind=nag_wp) :: bl(ndim), bu(ndim), opts(lopts), &
ruser(lruser), xb(ndim)
Integer :: iopts(liopts), itt(6), iuser(liuser)
! .. Executable Statements ..
! Print advisory information.
Write (nout,*) 'E05SAF Example Program Results'
Write (nout,*)
Write (nout,*) 'Minimization of the Schwefel function.'
Write (nout,*)
! Set problem specific values.
! Set box bounds.
bl(1:ndim) = -500.0_nag_wp
bu(1:ndim) = 500.0_nag_wp
! Determine the number of particles to be used in the simulation.
npar = 5*x06acf()
! Initialize the option arrays for E05SAF.
ifail = 0
Call e05zkf('Initialize = E05SAF',iopts,liopts,opts,lopts,ifail)
! Set the option SMP Callback Thread Safe to indicate the callback functions
! are indeed threadsafe. This must be done if using multiple threads.
ifail = 0
Call e05zkf('SMP Callback Thread Safe = Yes',iopts,liopts,opts,lopts, &
ifail)
! Query some default option values.
Write (nout,*) ' Default Option Queries:'
Write (nout,*)
ifail = 0
optstr = 'Boundary'
Call e05zlf(optstr,ivalue,rvalue,cvalue,optype,iopts,opts,ifail)
Call display_option(optstr,optype,ivalue,rvalue,cvalue)
ifail = 0
optstr = 'Maximum Iterations Completed'
Call e05zlf(optstr,ivalue,rvalue,cvalue,optype,iopts,opts,ifail)
Call display_option(optstr,optype,ivalue,rvalue,cvalue)
ifail = 0
optstr = 'Distance Tolerance'
Call e05zlf(optstr,ivalue,rvalue,cvalue,optype,iopts,opts,ifail)
Call display_option(optstr,optype,ivalue,rvalue,cvalue)
Write (nout,*)
! ------------------------------------------------------------------
Write (nout,*) '1. Solution without using coupled local minimizer.'
Write (nout,*)
! Set various options to non-default values if required.
ifail = 0
Call e05zkf('Repeatability = On',iopts,liopts,opts,lopts,ifail)
ifail = 0
Call e05zkf('Verify Gradients = Off',iopts,liopts,opts,lopts,ifail)
ifail = 0
Call e05zkf('Boundary = Hyperspherical',iopts,liopts,opts,lopts,ifail)
ifail = 0
Call e05zkf('Maximum iterations static = 150',iopts,liopts,opts,lopts, &
ifail)
ifail = 0
Call e05zkf('Repulsion Initialize = 30',iopts,liopts,opts,lopts,ifail)
ifail = 0
Call e05zkf('Repulsion Finalize = 30',iopts,liopts,opts,lopts,ifail)
! Call E05SAF to search for the global optimum.
! Non-zero IFAIL expected on exit here, so use IFAIL=1 (quiet) on entry.
ifail = 1
Call e05saf(ndim,npar,xb,fb,bl,bu,objfun_schwefel,monmod,iopts,opts, &
iuser,ruser,itt,inform,ifail)
! It is essential to test IFAIL on exit.
Select Case (ifail)
Case (0,1)
! No errors, best found optimum at xb returned in fb.
Call display_result(ndim,xb,fb,itt,inform)
Case (3)
! Exit flag set in OBJFUN or MONMOD and returned in INFORM.
Call display_result(ndim,xb,fb,itt,inform)
Case Default
! An error was detected. Print message since IFAIL=1 on entry.
Write (nout,99998) '** E05SAF returned with an error, IFAIL = ', ifail
End Select
! ------------------------------------------------------------------
Write (nout,*) '2. Solution using coupled local minimizer E04CBF'
Write (nout,*)
! Set an objective target.
ifail = 0
Write (optstr,99999) 'Target Objective Value', f_target
Call e05zkf(optstr,iopts,liopts,opts,lopts,ifail)
ifail = 0
Write (optstr,99999) 'Target Objective Tolerance', 1.0E-5_nag_wp
Call e05zkf(optstr,iopts,liopts,opts,lopts,ifail)
ifail = 0
Write (optstr,99999) 'Target Objective Safeguard', 1.0E-8_nag_wp
Call e05zkf(optstr,iopts,liopts,opts,lopts,ifail)
! Set the local minimizer to be E04CBF and set corresponding options.
ifail = 0
Call e05zkf('Local Minimizer = E04CBF',iopts,liopts,opts,lopts,ifail)
ifail = 0
Call e05zkf('Local Interior Iterations = 10',iopts,liopts,opts,lopts, &
ifail)
ifail = 0
Call e05zkf('Local Exterior Iterations = 20',iopts,liopts,opts,lopts, &
ifail)
ifail = 0
Write (optstr,99999) 'Local Interior Tolerance', 1.0E-4_nag_wp
Call e05zkf(optstr,iopts,liopts,opts,lopts,ifail)
ifail = 0
Write (optstr,99999) 'Local Exterior Tolerance', 1.0E-4_nag_wp
Call e05zkf(optstr,iopts,liopts,opts,lopts,ifail)
! Call E05SAF to search for the global optimum.
ifail = -1
Call e05saf(ndim,npar,xb,fb,bl,bu,objfun_schwefel,monmod,iopts,opts, &
iuser,ruser,itt,inform,ifail)
! It is essential to test IFAIL on exit.
Select Case (ifail)
Case (0,1)
! No errors, best found optimum at xb returned in fb.
Call display_result(ndim,xb,fb,itt,inform)
Case (3)
! Exit flag set in OBJFUN or MONMOD and returned in INFORM.
Call display_result(ndim,xb,fb,itt,inform)
Case Default
! An error was detected.
End Select
! -----------------------------------------------------------------
Write (nout,*) '3. Solution using coupled local minimizer E04DGF'
Write (nout,*)
! Set the local minimizer to be E04DGF and set corresponding options.
ifail = 0
Call e05zkf('Local Minimizer = E04DGF',iopts,liopts,opts,lopts,ifail)
ifail = 0
Call e05zkf('Local Interior Iterations = 5',iopts,liopts,opts,lopts, &
ifail)
ifail = 0
Call e05zkf('Local Exterior Iterations = 20',iopts,liopts,opts,lopts, &
ifail)
! Call E05SAF to search for the global optimum.
ifail = -1
Call e05saf(ndim,npar,xb,fb,bl,bu,objfun_schwefel,monmod,iopts,opts, &
iuser,ruser,itt,inform,ifail)
! It is essential to test IFAIL on exit.
Select Case (ifail)
Case (0,1)
! No errors, best found optimum at xb returned in fb.
Call display_result(ndim,xb,fb,itt,inform)
Case (3)
! Exit flag set in OBJFUN or MONMOD and returned in INFORM.
Call display_result(ndim,xb,fb,itt,inform)
Case Default
! An error was detected.
End Select
99999 Format (A,' = ',E32.16)
99998 Format (1X,A,I6)
End Program e05safe