NAG CL Interface
e02rbc (pade_​eval)

1 Purpose

2 Specification

3 Description

4 References

5 Arguments

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

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: $\mathbf{ia}$ – Integer Input

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 double Input

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: $\mathbf{ib}$ – Integer Input

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

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

5: $\mathbf{x}$ – double Input

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 7 in the Introduction to the NAG Library CL Interface).

6 Error Indicators and Warnings

NE_ALLOC_FAIL

Dynamic memory allocation failed.
See Section 3.1.2 in the Introduction to the NAG Library CL Interface 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 7.5 in the Introduction to the NAG Library CL Interface for further information.

NE_NO_LICENCE

Your licence key may have expired or may not have been installed correctly.
See Section 8 in the Introduction to the NAG Library CL Interface 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

10.2 Program Data

10.3 Program Results