NAG Library Function Document

nag_1d_pade_eval (e02rbc)

1

Purpose

2

Specification

3

Description

4

References

5

Arguments

1:    $\mathbf{a}\left[\mathbf{ia}\right]$ – const doubleInput

On entry: $\mathbf{a}\left[\mathit{j}\right]$, for $\mathit{j}=1,2,\dots ,l+1$, must contain the value of the coefficient $a_{\mathit{j}}$ in the numerator of the rational function.

2:    $\mathbf{ia}$ – IntegerInput

On entry: the value of $l+1$, where $l$ is the degree of the numerator.

Constraint: $\mathbf{ia}\ge 1$.

3:    $\mathbf{b}\left[\mathbf{ib}\right]$ – const doubleInput

On entry: $\mathbf{b}\left[\mathit{k}\right]$, for $\mathit{k}=1,2,\dots ,m+1$, must contain the value of the coefficient $b_k$ in the denominator of the rational function.

Constraint: if $\mathbf{ib}=1$, $\mathbf{b}\left[0\right]\ne 0.0$.

4:    $\mathbf{ib}$ – IntegerInput

On entry: the value of $m+1$, where $m$ is the degree of the denominator.

Constraint: $\mathbf{ib}\ge 1$.

5:    $\mathbf{x}$ – doubleInput

On entry: the point $x$ at which the rational function is to be evaluated.

6:    $\mathbf{ans}$ – double *Output

On exit: the result of evaluating the rational function at the given point $x$.

7:    $\mathbf{fail}$ – NagError *Input/Output

The NAG error argument (see Section 3.7 in How to Use the NAG Library and its Documentation).

6

Error Indicators and Warnings

NE_ALLOC_FAIL

Dynamic memory allocation failed.
See Section 2.3.1.2 in How to Use the NAG Library and its Documentation for further information.

NE_BAD_PARAM

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

NE_INT

On entry, $\mathbf{ia}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{ia}\ge 1$.

On entry, $\mathbf{ib}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{ib}\ge 1$.

NE_INT_ARRAY

The first ib entries in b are zero: $\mathbf{ib}=〈\mathit{\text{value}}〉$.

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.
See Section 2.7.6 in How to Use the NAG Library and its Documentation for further information.

NE_NO_LICENCE

Your licence key may have expired or may not have been installed correctly.
See Section 2.7.5 in How to Use the NAG Library and its Documentation for further information.

NE_POLE_PRESENT

Evaluation at or near a pole.

7

Accuracy

8

Parallelism and Performance

9

Further Comments

10

Example

10.1

Program Text

Program Text (e02rbce.c)

10.2

Program Data

10.3

Program Results

Program Results (e02rbce.r)