1: $x$ – Real (Kind=nag_wp) Input: On entry: the argument $λ$ of the function.
2: $rcomm (322)$ – Real (Kind=nag_wp) array Communication Array: On entry: this must be the same argument rcomm as returned by a previous call to g01zuf.
3: $ifail$ – 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:

$ifail = 1$: Either the initialization routine has not been called prior to the first call of this routine or a communication array 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

At least five significant digits are usually correct.

g01euf is not threaded in any implementation.

g01euf can be called repeatedly with different values of

λ

provided that the values of

κ

and

β^{2}

remain unchanged between calls. Otherwise, g01zuf must be called again. This is illustrated in Section 10.

This example evaluates

Φ_{V} (λ; κ, β^{2})

λ = 0.1

κ = 2.5

and

β^{2} = 0.7

, and prints the results.

Interfaces: FL CL AD

g01eu: FL CL AD