NAG Library Manual, Mark 27.1
Interfaces:  FL   CL   CPP   AD 
NAG AD Library Introduction
C05 (Roots) Chapter Contents
C05 (Roots) Chapter Introduction (FL)
c05qd:  FL   CL   CPP   AD 

NAG AD Library
c05qd_a1w_f (sys_func_rcomm_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.
NAG Library Manual, Mark 27.1
Interfaces:  FL   CL   CPP   AD 
NAG AD Library Introduction
C05 (Roots) Chapter Contents
C05 (Roots) Chapter Introduction (FL)
c05qd:  FL   CL   CPP   AD 

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© The Numerical Algorithms Group Ltd. 2020
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1 Purpose

c05qd_a1w_f is the adjoint version of the primal routine c05qdf.

2 Specification

Fortran Interface
Subroutine c05qd_a1w_f ( ad_handle, irevcm, n, x, fvec, xtol, ml, mu, epsfcn, mode, diag, factor, fjac, r, qtf, iwsav, rwsav, ifail)
Integer, Intent (In) :: n, ml, mu, mode
Integer, Intent (Inout) :: irevcm, iwsav(17), ifail
Type (nagad_a1w_w_rtype), Intent (In) :: xtol, epsfcn, factor
Type (nagad_a1w_w_rtype), Intent (Inout) :: x(n), fvec(n), diag(n), fjac(n,n), r(n*(n+1)/2), qtf(n), rwsav(4*n+10)
Type (c_ptr), Intent (Inout) :: ad_handle
C++ Header Interface
#include <nagad.h>
void c05qd_a1w_f_ ( void *&ad_handle, Integer &irevcm, const Integer &n, nagad_a1w_w_rtype x[], nagad_a1w_w_rtype fvec[], const nagad_a1w_w_rtype &xtol, const Integer &ml, const Integer &mu, const nagad_a1w_w_rtype &epsfcn, const Integer &mode, nagad_a1w_w_rtype diag[], const nagad_a1w_w_rtype &factor, nagad_a1w_w_rtype fjac[], nagad_a1w_w_rtype r[], nagad_a1w_w_rtype qtf[], Integer iwsav[], nagad_a1w_w_rtype rwsav[], Integer &ifail)
The routine may be called by the names c05qd_a1w_f or nagf_roots_sys_func_rcomm_a1w. The corresponding t1w and p0w variants of this routine are also available.

3 Description

c05qd_a1w_f is the adjoint version of the primal routine c05qdf.
c05qdf is a comprehensive reverse communication routine that finds a solution of a system of nonlinear equations by a modification of the Powell hybrid method. For further information see Section 3 in the documentation for c05qdf.

4 References

Moré J J, Garbow B S and Hillstrom K E (1980) User guide for MINPACK-1 Technical Report ANL-80-74 Argonne National Laboratory
Powell M J D (1970) A hybrid method for nonlinear algebraic equations Numerical Methods for Nonlinear Algebraic Equations (ed P Rabinowitz) Gordon and Breach

5 Arguments

In addition to the arguments present in the interface of the primal routine, c05qd_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: irevcm – Integer Input/Output
3: n – Integer Input
4: x(n) – Type (nagad_a1w_w_rtype) array Input/Output
5: fvec(n) – Type (nagad_a1w_w_rtype) array Input/Output
6: xtol – Type (nagad_a1w_w_rtype) Input
7: ml – Integer Input
8: mu – Integer Input
9: epsfcn – Type (nagad_a1w_w_rtype) Input
10: mode – Integer Input
11: diag(n) – Type (nagad_a1w_w_rtype) array Input/Output
12: factor – Type (nagad_a1w_w_rtype) Input
13: fjac(n, n) – Type (nagad_a1w_w_rtype) array Input/Output
14: r(n×(n+1)/2) – Type (nagad_a1w_w_rtype) array Input/Output
15: qtf(n) – Type (nagad_a1w_w_rtype) array Input/Output
16: iwsav(17) – Integer array Communication Array
17: rwsav(4×n+10) – Type (nagad_a1w_w_rtype) array Communication Array
18: ifail – Integer Input/Output

6 Error Indicators and Warnings

c05qd_a1w_f preserves all error codes from c05qdf 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

c05qd_a1w_f is not threaded in any implementation.

9 Further Comments

None.

10 Example

The following examples are variants of the example for c05qdf, modified to demonstrate calling the NAG AD Library.

10.1 Adjoint mode (a1w)

LanguageSource FileDataResults
Fortranc05qd_a1w_fe.f90Nonec05qd_a1w_fe.r
C++c05qd_a1w_hcppe.cppNonec05qd_a1w_hcppe.r

10.2 Tangent mode (t1w)

LanguageSource FileDataResults
Fortranc05qd_t1w_fe.f90Nonec05qd_t1w_fe.r
C++c05qd_t1w_hcppe.cppNonec05qd_t1w_hcppe.r

10.3 Passive mode (p0w)

LanguageSource FileDataResults
Fortranc05qd_p0w_fe.f90Nonec05qd_p0w_fe.r
C++c05qd_p0w_hcppe.cppNonec05qd_p0w_hcppe.r
NAG Library Manual, Mark 27.1
Interfaces:  FL   CL   CPP   AD 
NAG AD Library Introduction
C05 (Roots) Chapter Contents
C05 (Roots) Chapter Introduction (FL)
c05qd:  FL   CL   CPP   AD 
© The Numerical Algorithms Group Ltd. 2020