NAG AD Library
f03bn (complex_gen)

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1 Purpose

f03bn is the AD Library version of the primal routine f03bnf. Based (in the C++ interface) on overload resolution, f03bn can be used for primal, tangent and adjoint evaluation. It supports tangents and adjoints of first order.

2 Specification

Fortran Interface
Subroutine f03bn_AD_f ( n, a, lda, ipiv, d, id, ifail)
Integer, Intent (In) :: n, lda, ipiv(n)
Integer, Intent (Inout) :: ifail
Integer, Intent (Out) :: id(2)
ADCTYPE, Intent (In) :: a(lda,*)
ADCTYPE, Intent (Out) :: d
Type (c_ptr), Intent (Inout) :: ad_handle
Corresponding to the overloaded C++ function, the Fortran interface provides five routines with names reflecting the type used for active real arguments. The actual subroutine and type names are formed by replacing AD and ADTYPE in the above as follows:
when ADTYPE is Real(kind=nag_wp) then AD is p0w
when ADTYPE is Type(nagad_a1w_w_rtype) then AD is a1w
when ADTYPE is Type(nagad_t1w_w_rtype) then AD is t1w
C++ Interface
#include <dco.hpp>
#include <nagad.h>
namespace nag {
namespace ad {
void f03bn ( handle_t &ad_handle, const Integer &n, const ADCTYPE a[], const Integer &lda, const Integer ipiv[], ADCTYPE &d, Integer id[], Integer &ifail)
The function is overloaded on ADTYPE which represents the type of active arguments. ADTYPE may be any of the following types:
Note: this function can be used with AD tools other than dco/c++. For details, please contact NAG.

3 Description

f03bn is the AD Library version of the primal routine f03bnf.
f03bnf computes the determinant of a complex n×n matrix A. f07arf must be called first to supply the matrix A in factorized form. For further information see Section 3 in the documentation for f03bnf.

4 References

Wilkinson J H and Reinsch C (1971) Handbook for Automatic Computation II, Linear Algebra Springer–Verlag

5 Arguments

In addition to the arguments present in the interface of the primal routine, f03bn 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_handlenag::ad::handle_t Input/Output
On entry: a configuration object that holds information on the differentiation strategy. Details on setting the AD strategy are described in AD handle object in the NAG AD Library Introduction.
2: n – Integer Input
3: a(lda, *) – ADCTYPE array Input
4: lda – Integer Input
5: ipiv(n) – Integer array Input
6: d – ADCTYPE Output
7: id(2) – Integer array Output
8: ifail – Integer Input/Output

6 Error Indicators and Warnings

f03bn preserves all error codes from f03bnf and in addition can return:
An unexpected AD error has been triggered by this routine. Please contact NAG.
See Error Handling in the NAG AD Library Introduction for further information.
The routine was called using a strategy that has not yet been implemented.
See AD Strategies in the NAG AD Library Introduction for further information.
A C++ exception was thrown.
The error message will show the details of the C++ exception text.
Dynamic memory allocation failed for AD.
See Error Handling in the NAG AD Library Introduction for further information.

7 Accuracy

Not applicable.

8 Parallelism and Performance

f03bn is not threaded in any implementation.

9 Further Comments


10 Example

The following examples are variants of the example for f03bnf, modified to demonstrate calling the NAG AD Library.
Description of the primal example.
This example calculates the determinant of the complex matrix
( 1 1+2i 2+10i 1+i 3i −5+14i 1+i 5i −8+20i ) .  

10.1 Adjoint modes

Language Source File Data Results
Fortran f03bn_a1w_fe.f90 f03bn_a1w_fe.d f03bn_a1w_fe.r
C++ f03bn_a1w_hcppe.cpp f03bn_a1w_hcppe.d f03bn_a1w_hcppe.r

10.2 Tangent modes

Language Source File Data Results
Fortran f03bn_t1w_fe.f90 f03bn_t1w_fe.d f03bn_t1w_fe.r
C++ f03bn_t1w_hcppe.cpp f03bn_t1w_hcppe.d f03bn_t1w_hcppe.r

10.3 Passive mode

Language Source File Data Results
Fortran f03bn_p0w_fe.f90 f03bn_p0w_fe.d f03bn_p0w_fe.r
C++ f03bn_p0w_hcppe.cpp f03bn_p0w_hcppe.d f03bn_p0w_hcppe.r