NAG FL Interface
s14aff (psi_​deriv_​complex)

1 Purpose

2 Specification

3 Description

4 References

5 Arguments

1: $\mathbf{z}$ – Complex (Kind=nag_wp) Input

On entry: the argument $z$ of the function.

Constraint: $\mathrm{Re}\left(\mathbf{z}\right)$ must not be ‘too close’ (see Section 6) to a non-positive integer when $\mathrm{Im}\left(\mathbf{z}\right)=0.0$.

2: $\mathbf{k}$ – Integer Input

On entry: the function ${\psi }^{\left(k\right)}\left(z\right)$ to be evaluated.

Constraint: $0\le \mathbf{k}\le 4$.

3: $\mathbf{ifail}$ – Integer Input/Output

On entry: ifail must be set to $0$, $\mathrm{-1}$ 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 $\mathrm{-1}$ means that an error message is printed while a value of $1$ means that it is not.

If halting is not appropriate, the value $\mathrm{-1}$ or $1$ is recommended. If message printing is undesirable, then the value $1$ is recommended. Otherwise, the value $0$ is recommended. When the value $-\mathbf{1}$ or $\mathbf{1}$ is used it is essential to test the value of ifail on exit.

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

6 Error Indicators and Warnings

$\mathbf{ifail}=1$

On entry, $\mathbf{k}=⟨\mathit{\text{value}}⟩$.
Constraint: $\mathbf{k}\le 4$.

On entry, $\mathbf{k}=⟨\mathit{\text{value}}⟩$.
Constraint: $\mathbf{k}\ge 0$.

On entry, $\mathrm{Re}\left(\mathbf{z}\right)$ is ‘too close’ to a non-positive integer when $\mathrm{Im}\left(\mathbf{z}\right)=0.0$: $\mathrm{Re}\left(\mathbf{z}\right)=⟨\mathit{\text{value}}⟩$, $\mathrm{nint}\left(\mathrm{Re}\left(\mathbf{z}\right)\right)=⟨\mathit{\text{value}}⟩$.

$\mathbf{ifail}=2$

Evaluation abandoned due to likelihood of overflow.

$\mathbf{ifail}=-99$

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.

$\mathbf{ifail}=-399$

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.

$\mathbf{ifail}=-999$

Dynamic memory allocation failed.

See Section 9 in the Introduction to the NAG Library FL Interface for further information.

7 Accuracy

8 Parallelism and Performance

9 Further Comments

10 Example

10.1 Program Text

10.2 Program Data

10.3 Program Results