NAG Library Function Document

nag_init_vavilov (g01zuc)

1  Purpose

2  Specification

3  Description

4  References

5  Arguments

1:     rkappa – doubleInput

On entry: the argument $\kappa$ of the function.

Constraint: $0.01\le \mathbf{rkappa}\le 10.0$.

2:     beta2 – doubleInput

On entry: the argument ${\beta }^2$ of the function.

Constraint: $0.0\le \mathbf{beta2}\le 1.0$.

3:     mode – IntegerInput

On entry: if $\mathbf{mode}=0$, then nag_prob_density_vavilov (g01muc) is to be called after the call to nag_init_vavilov (g01zuc). Otherwise, nag_prob_vavilov (g01euc) is to be called.

4:     xl – double *Output

On exit: $x_l$, a threshold value below which ${\varphi }_V\left(\lambda \text{;}\kappa ,{\beta }^2\right)$ will be set to zero by nag_prob_density_vavilov (g01muc) and ${\Phi }_V\left(\lambda \text{;}\kappa ,{\beta }^2\right)$ will be set to zero by nag_prob_vavilov (g01euc) if $\lambda <x_l$.

5:     xu – double *Output

On exit: $x_u$, a threshold value above which ${\varphi }_V\left(\lambda \text{;}\kappa ,{\beta }^2\right)$ will be set to zero by nag_prob_density_vavilov (g01muc) and ${\Phi }_V\left(\lambda \text{;}\kappa ,{\beta }^2\right)$ will be set to unity by nag_prob_vavilov (g01euc) if $\lambda >x_u$.

6:     comm_arr[$322$] – doubleCommunication Array

On exit: this argument should be passed unchanged to nag_prob_vavilov (g01euc) or nag_prob_density_vavilov (g01muc).

7:     fail – NagError *Input/Output

The NAG error argument (see Section 3.6 in the Essential Introduction).

6  Error Indicators and Warnings

NE_BAD_PARAM

On entry, argument $〈\mathit{\text{value}}〉$ had an illegal value.

NE_INTERNAL_ERROR

An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact NAG for assistance.

NE_REAL

On entry, $\mathbf{beta2}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{beta2}\le 1.0$.

On entry, $\mathbf{beta2}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{beta2}\ge 0.0$.

On entry, $\mathbf{rkappa}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{rkappa}\le 10.0$.

On entry, $\mathbf{rkappa}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{rkappa}\ge 0.01$.

7  Accuracy

8  Further Comments

9  Example