x10af_AD_f is only required from C and Fortran. x10af_AD_f sets the length of the iuser array in a configuration data object. This enables/disables checkpointing for symbolic adjoint routines. The set of possible values are: -1, 0 and greater 0.

2 Specification

Fortran Interface

Subroutine x10af_AD_f (

ad_handle, iusersize, ifail)

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

To be consistent with the naming scheme for other routines in the AD Library, five routines are available with names formed by replacing AD in the above by one of p0w, a1w, t1w, a1t1w or t2w.

C++ Header Interface

#include <nagad.h>

extern "C" {

void	x10af_AD_f_ (void *&ad_handle, const Integer &iusersize, Integer &ifail)

}

To be consistent with the naming scheme for other functions in the AD Library, five functions are available with names formed by replacing AD in the above by one of p0w, a1w, t1w, a1t1w or t2w.

3 Description

x10af_AD_f sets the length of the iuser array in the configuration data object. It is relevant in symbolic adjoint mode routines and enables/disables checkpointing of iuser array. The values currently allowed are -1, 0, and greater 0. 0 is default and generates an error, if iuser is not nullptr. -1 disables checkpoint. Any positive number defines the length of the array and enables checkpointing in symbolic mode. This routine must be called after a call to x10aa_AD_f (to create a handle to the configuration data object) and prior to the call of the computational NAG AD Library routines for which the information is set.

4 References

None.

5 Arguments

1: $ad_handle$ – Pointer to AD Data Input/Output: On entry: a handle to the AD configuration data object, as created by x10aa_AD_f.

On exit: holds a handle to the internal data structure where information about the length of the iuser array has been stored. You must not change the handle other than via NAG AD Library calls until it is destroyed by x10ab_AD_f.
2: $iusersize$ – Integer Input: On entry: the size of the user declared array iuser.

Constraint: $iusersize \geq −1$ .
3: $ifail$ – Integer Input/Output: On entry: ifail must be set to $0$ , $−1$ or $1$ to set behaviour on detection of an error; these values have no effect when no error is detected.
A value of $0$ causes the printing of an error message and program execution will be halted; otherwise program execution continues. A value of $−1$ means that an error message is printed while a value of $1$ means that it is not.

If halting is not appropriate, the value $−1$ or $1$ is recommended. If message printing is undesirable, then the value $1$ is recommended. Otherwise, the value $0$ is recommended. 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.

$ifail = 2$: On entry: unexpected value of iusersize.
Constraint: $iusersize \geq −1$ .

$ifail = - 99$: 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.