! C05AY_A1W_F Example Program Text
! Mark 28.4 Release. NAG Copyright 2022.
Module c05ay_a1w_fe_mod
! C05AY_A1W_F Example Program Module:
! Parameters and User-defined Routines
! .. Use Statements ..
Use iso_c_binding, Only: c_funloc, c_int, c_ptr
Use nagad_library, Only: exp, nagad_a1w_get_derivative, &
nagad_a1w_inc_derivative, &
nagad_a1w_ir_register_variable, &
nagad_a1w_w_rtype, nagad_primal, x10ad_a1w_f, &
x10ba_a1w_f, x10bb_a1w_f, x10bd_a1w_f, &
x10be_a1w_f, x10bj_a1w_f, x10ce_a1w_f, &
x10cj_a1w_f, Assignment (=), Operator (-), &
Operator (*)
Use nag_library, Only: nag_wp
! .. Implicit None Statement ..
Implicit None
! .. Accessibility Statements ..
Private
Public :: cb_sym, f_a1w
! .. Parameters ..
Integer, Parameter, Public :: nin = 5, nout = 6
Contains
Subroutine f_a1w(ad_handle,x,z,iuser,ruser)
! .. Use Statements ..
Use nagad_library, Only: nagad_algorithmic, nagad_symbolic
! .. Scalar Arguments ..
Type (c_ptr), Intent (Inout) :: ad_handle
Type (nagad_a1w_w_rtype), Intent (In) :: x
Type (nagad_a1w_w_rtype), Intent (Out) :: z
! .. Array Arguments ..
Type (nagad_a1w_w_rtype), Intent (Inout) :: ruser(*)
Integer, Intent (Inout) :: iuser(*)
! .. Local Scalars ..
Type (c_ptr) :: cb_handle
Integer :: cb_mode, ifail, mode
! .. Executable Statements ..
ifail = 0
Call x10ad_a1w_f(ad_handle,mode,ifail)
z = 0.0_nag_wp
If (mode==nagad_algorithmic) Then
! Use module extensions to operators and intrinsics.
z = exp(-x) - x*ruser(1)
Else If (mode==nagad_symbolic) Then
Call x10bd_a1w_f(ad_handle,cb_mode,ifail)
If (cb_mode==nagad_primal) Then
! Evaluate primal only
z%value = exp(-x%value) - x%value*ruser(1)%value
z%tapeindex = 0
Else
! Adjoint w.r.t to x or ruser
! Create callback data object
ifail = 0
Call x10ba_a1w_f(cb_handle,ifail)
! Write cb_mode to object
Call x10be_a1w_f(cb_handle,cb_mode,ifail)
! Write inputs to object
Call x10bj_a1w_f(cb_handle,x,ifail)
Call x10bj_a1w_f(cb_handle,ruser(1),ifail)
! Evaluate primal
z%value = exp(-x%value) - x%value*ruser(1)%value
z%tapeindex = 0
! Register output
Call nagad_a1w_ir_register_variable(z)
! Write output to object
Call x10bj_a1w_f(cb_handle,z,ifail)
! Insert callback
Call x10bb_a1w_f(cb_handle,c_funloc(cb_sym),ifail)
End If
End If
Return
End Subroutine f_a1w
Subroutine cb_sym(callmode,cb_handle) Bind (C)
! .. Use Statements ..
Use nagad_library, Only: nagad_dall, nagad_dparam, nagad_dstate
! .. Scalar Arguments ..
Type (c_ptr), Value :: cb_handle
Integer (Kind=c_int), Value :: callmode
! .. Local Scalars ..
Type (nagad_a1w_w_rtype) :: ruser, x, z
Real (Kind=nag_wp) :: ra, xa, za
Integer :: cb_mode, ifail
! .. Executable Statements ..
If (callmode==1) Then
Return
End If
! Extract data from callback data object
ifail = 0
Call x10ce_a1w_f(cb_handle,cb_mode,ifail)
Call x10cj_a1w_f(cb_handle,x,ifail)
Call x10cj_a1w_f(cb_handle,ruser,ifail)
Call x10cj_a1w_f(cb_handle,z,ifail)
za = nagad_a1w_get_derivative(z)
If (cb_mode==nagad_dstate .Or. cb_mode==nagad_dall) Then
! d/dx
xa = (-ruser%value-exp(-x%value))*za
Call nagad_a1w_inc_derivative(x,xa)
End If
If (cb_mode==nagad_dparam .Or. cb_mode==nagad_dall) Then
! d/druser
ra = -x%value*za
Call nagad_a1w_inc_derivative(ruser,ra)
End If
End Subroutine cb_sym
End Module c05ay_a1w_fe_mod
Program c05ay_a1w_fe
! C05AY_A1W_F Example Main Program
! .. Use Statements ..
Use c05ay_a1w_fe_mod, Only: f_a1w, nin, nout
Use iso_c_binding, Only: c_ptr
Use nagad_library, Only: c05ay_a1w_f, nagad_a1w_get_derivative, &
nagad_a1w_ir_create => x10za_a1w_f, &
nagad_a1w_ir_interpret_adjoint_sparse, &
nagad_a1w_ir_register_variable, &
nagad_a1w_ir_remove, nagad_a1w_set_derivative, &
nagad_a1w_w_rtype, nagad_algorithmic, &
x10aa_a1w_f, x10ab_a1w_f, x10ac_a1w_f, &
x10ae_a1w_f, x10af_a1w_f, Assignment (=)
Use nag_library, Only: nag_wp
! .. Implicit None Statement ..
Implicit None
! .. Local Scalars ..
Type (nagad_a1w_w_rtype) :: a, b, eps, eta, x
Type (c_ptr) :: ad_handle
Real (Kind=nag_wp) :: ar, br, da, db, druser, epsr, etar, &
rr
Integer :: ifail, mode
! .. Local Arrays ..
Type (nagad_a1w_w_rtype) :: ruser(1)
Integer :: iuser(1)
! .. Executable Statements ..
Write (nout,*) 'C05AY_A1W_F Example Program Results'
! Skip first line of data file
Read (nin,*)
! Read problem parameters
Read (nin,*) ar
Read (nin,*) br
Read (nin,*) epsr
Read (nin,*) etar
Read (nin,*) rr
a = ar
b = br
eps = epsr
eta = etar
ruser(1) = rr
! Create AD tape
Call nagad_a1w_ir_create
! Create AD configuration data object
ifail = 0
Call x10aa_a1w_f(ad_handle,ifail)
! Read AD computational mode
Read (nin,*) mode
! Set this mode.
Call x10ac_a1w_f(ad_handle,mode,ifail)
! Register variables to differentiate w.r.t.
Call nagad_a1w_ir_register_variable(a)
Call nagad_a1w_ir_register_variable(b)
Call nagad_a1w_ir_register_variable(ruser)
! Call AD routine
ifail = 0
Call x10ae_a1w_f(ad_handle,1,ifail)
ifail = 0
Call x10af_a1w_f(ad_handle,-1,ifail)
Call c05ay_a1w_f(ad_handle,a,b,eps,eta,f_a1w,x,iuser,ruser,ifail)
! Setup evaluation of derivatives via adjoints
Call nagad_a1w_set_derivative(x,1.0_nag_wp)
ifail = 0
Call nagad_a1w_ir_interpret_adjoint_sparse(ifail)
Write (nout,*)
Write (nout,*) ' Derivatives calculated: First order adjoints'
If (mode==nagad_algorithmic) Then
Write (nout,*) ' Computational mode : algorithmic'
Else
Write (nout,*) ' Computational mode : symbolic'
End If
! Get derivatives
da = nagad_a1w_get_derivative(a)
db = nagad_a1w_get_derivative(b)
druser = nagad_a1w_get_derivative(ruser(1))
Write (nout,*)
Write (nout,99999) ' Solution, x =', x%value
Write (nout,*) ' Derivatives:'
Write (nout,99999) ' d/da(x) =', da
Write (nout,99999) ' d/db(x) =', db
Write (nout,99999) ' d/druser(x) =', druser
99999 Format (1X,A,1X,E12.5)
! Remove computational data object and tape
Call x10ab_a1w_f(ad_handle,ifail)
Call nagad_a1w_ir_remove
End Program c05ay_a1w_fe