x10ab_a1w_f deletes a configuration data structure, created by x10aa_a1w_f and used by the NAG AD Library. It must be called following the final call to routines from the NAG AD Library as listed in the Introduction to the NAG AD Library including any other routine in Chapter X10.

2 Specification

Fortran Interface

Subroutine x10ab_a1w_f (

ad_handle, ifail)

Integer, Intent (Inout)	::	ifail
Type (c_ptr), Intent (Inout)	::	ad_handle

C++ Header Interface

#include <nagad.h>

extern "C" {

void	x10ab_a1w_f_ (void *&ad_handle, Integer &ifail)

}

The routine may be called by the names x10ab_a1w_f or nagf_adutils_config_handle_destroy_a1w.

3 Description

x10ab_a1w_f deletes a configuration data object, freeing the handle to the data object. This handle will have been created by a prior call to x10aa_a1w_f and passed to any routine in the NAG AD Library as listed in the Introduction to the NAG AD Library. The object must always be destroyed by a call to x10ab_a1w_f prior to exiting the application in which it was created.

3.1 Life Cycle of the Handle

Each handle should pass four stages in its life: initialization; mode setting; problem solution using the NAG AD Library; and, destruction.

The initialization by x10aa_a1w_f and destruction by x10ab_a1w_f mark the beginning and the end of the life of the handle. During this time the handle must only be modified by NAG AD Library routines. Working with a handle which has not been properly initialized is potentially very dangerous as it may cause unpredictable behaviour.

After the handle has been initialized, two routines are provided to set or get the computational mode to be used in algorithmic differentiation.

The handle is then passed to the computational routines of the NAG AD Library.

When all AD computation is completed, the handle must be destroyed by x10ab_a1w_f. When more than one handle has been initialized (e.g., for different computational modes) then each handle must be destroyed separately.

4 References

None.

5 Arguments

1: $ad_handle$ – Type (c_ptr) Input/Output: On entry: contains a handle to the AD configuration data object.

On exit: the handle is destroyed.
2: $ifail$ – Integer Input/Output: On entry: ifail must be set to $0$ , $- 1 or 1$ . If you are unfamiliar with this argument you should refer to Section 4 in the Introduction to the NAG Library FL Interface for details.
For environments where it might be inappropriate to halt program execution when an error is detected, the value $- 1 or 1$ is recommended. If the output of error messages is undesirable, then the value $1$ is recommended. Otherwise, if you are not familiar with this argument, the recommended value is $0$ . When the value $- 1 or 1$ is used it is essential to test the value of ifail on exit.

On exit: $ifail = 0$ unless the routine detects an error or a warning has been flagged (see Section 6).

6 Error Indicators and Warnings

If on entry

ifail = 0

- 1

, explanatory error messages are output on the current error message unit (as defined by x04aaf).

Errors or warnings detected by the routine:

$ifail = 1$: On entry: ad_handle is not a valid handle for the AD computational data object. Either ad_handle has not been initialized or it has become corrupted.

$ifail = - 99$: An unexpected error has been triggered by this routine. Please contact NAG.
See Section 7 in the Introduction to the NAG Library FL Interface for further information.

$ifail = - 399$: Your licence key may have expired or may not have been installed correctly.
See Section 8 in the Introduction to the NAG Library FL Interface for further information.

$ifail = - 999$: Dynamic memory allocation failed.
See Section 9 in the Introduction to the NAG Library FL Interface for further information.

7 Accuracy

Not applicable.

8 Parallelism and Performance

x10ab_a1w_f is not threaded in any implementation.

9 Further Comments

None.

10 Example

See examples for computational routines in the NAG AD Library, for example, Section 10 in c05ay_a1w_f.

NAG Library Manual, Mark 27

Interfaces: FL CL AD

NAG AD Interface Introduction

X10 (Adutils) Chapter Contents

X10 (Adutils) Chapter Introduction

x10ab: FL CL AD

NAG AD Libraryx10ab_a1w_f (config_​handle_​destroy_a1w)

▸▿ Contents

1 Purpose