NAG AD Library
e04wb_a1w_f (nlp1_init_a1w)

Note: a1w denotes that first order adjoints are computed in working precision; this has the corresponding argument type nagad_a1w_w_rtype. Also available is the t1w (first order tangent linear) mode, the interface of which is implied by replacing a1w by t1w throughout this document. Additionally, the p0w (passive interface, as alternative to the FL interface) mode is available and can be inferred by replacing of active types by the corresponding passive types. The method of codifying AD implementations in the routine name and corresponding argument types is described in the NAG AD Library Introduction.

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NAG Library Manual, Mark 27.1

Interfaces: FL CL CPP AD

NAG AD Library Introduction

E04 (Opt) Chapter Contents

E04 (Opt) Chapter Introduction (FL)

e04wb: FL CL CPP AD

▸▿ Contents

1 Purpose

2 Specification

3 Description

4 References

5 Arguments

6 Error Indicators and Warnings

7 Accuracy

8 Parallelism and Performance

9 Further Comments

▸▿ 10 Example

10.1 Adjoint mode (a1w)

10.2 Tangent mode (t1w)

10.3 Passive mode (p0w)

1 Purpose

e04wb_a1w_f is the adjoint version of the primal routine e04wbf.

2 Specification

Fortran Interface

Subroutine e04wb_a1w_f (

ad_handle, rname, cwsav, lcwsav, lwsav, llwsav, iwsav, liwsav, rwsav, lrwsav, ifail)

Integer, Intent (In)	::	lcwsav, llwsav, liwsav, lrwsav
Integer, Intent (Inout)	::	ifail
Integer, Intent (Out)	::	iwsav(liwsav)
Type (nagad_a1w_w_rtype), Intent (Out)	::	rwsav(lrwsav)
Logical, Intent (Out)	::	lwsav(llwsav)
Character (*), Intent (In)	::	rname
Character (80), Intent (Out)	::	cwsav(lcwsav)
Type (c_ptr), Intent (Inout)	::	ad_handle

C++ Header Interface

#include <nagad.h>

void e04wb_a1w_f_ (

void *&ad_handle, const char *rname, char *cwsav[], const Integer &lcwsav, logical lwsav[], const Integer &llwsav, Integer iwsav[], const Integer &liwsav, nagad_a1w_w_rtype rwsav[], const Integer &lrwsav, Integer &ifail, const Charlen length_rname, const Charlen length_cwsav)

The routine may be called by the names e04wb_a1w_f or nagf_opt_nlp1_init_a1w. The corresponding t1w and p0w variants of this routine are also available.

3 Description

e04wb_a1w_f is the adjoint version of the primal routine e04wbf.

e04wbf is used to initialize routines e04dga, e04mfa, e04nca, e04nfa, e04nka, e04uca, e04ufa, e04uga or e04usa. For further information see Section 3 in the documentation for e04wbf.

4 References

5 Arguments

In addition to the arguments present in the interface of the primal routine, e04wb_a1w_f includes some arguments specific to AD.

A brief summary of the AD specific arguments is given below. For the remainder, links are provided to the corresponding argument from the primal routine. A tooltip popup for all arguments can be found by hovering over the argument name in Section 2 and in this section.

1: ad_handle – Type (c_ptr) Input/Output: On entry: a handle to the AD configuration data object, as created by x10aa_a1w_f.
2: rname – character Input
3: cwsav(lcwsav) – character array Communication Array
4: lcwsav – Integer Input
5: lwsav(llwsav) – logical array Communication Array
6: llwsav – Integer Input
7: iwsav(liwsav) – Integer array Communication Array
8: liwsav – Integer Input
9: rwsav(lrwsav) – Type (nagad_a1w_w_rtype) array Communication Array
10: lrwsav – Integer Input
11: ifail – Integer Input/Output

6 Error Indicators and Warnings

e04wb_a1w_f preserves all error codes from e04wbf and in addition can return:

$ifail = - 89$: An unexpected AD error has been triggered by this routine. Please contact NAG.
See Section 4.8.2 in the NAG AD Library Introduction for further information.

$ifail = - 899$: Dynamic memory allocation failed for AD.
See Section 4.8.1 in the NAG AD Library Introduction for further information.

7 Accuracy

Not applicable.

8 Parallelism and Performance

e04wb_a1w_f is not threaded in any implementation.

9 Further Comments

None.

10 Example

The following examples are variants of the example for e04wbf, modified to demonstrate calling the NAG AD Library.

10.1 Adjoint mode (a1w)

Language	Source File	Data	Results
Fortran	e04wb_a1w_fe.f90	e04wb_a1w_fe.d	e04wb_a1w_fe.r
C++	e04wb_a1w_hcppe.cpp	e04wb_a1w_hcppe.d	e04wb_a1w_hcppe.r

10.2 Tangent mode (t1w)

Language	Source File	Data	Results
Fortran	e04wb_t1w_fe.f90	e04wb_t1w_fe.d	e04wb_t1w_fe.r
C++	e04wb_t1w_hcppe.cpp	e04wb_t1w_hcppe.d	e04wb_t1w_hcppe.r

10.3 Passive mode (p0w)

Language	Source File	Data	Results
Fortran	e04wb_p0w_fe.f90	e04wb_p0w_fe.d	e04wb_p0w_fe.r
C++	e04wb_p0w_hcppe.cpp	e04wb_p0w_hcppe.d	e04wb_p0w_hcppe.r