NAG CL Interface
e01bgc (dim1_​monotonic_​deriv)

1 Purpose

2 Specification

3 Description

4 References

5 Arguments

1: $\mathbf{n}$ – Integer Input

On entry: n must be unchanged from the previous call of e01bec.

2: $\mathbf{x}\left[\mathbf{n}\right]$ – const double Input

3: $\mathbf{f}\left[\mathbf{n}\right]$ – const double Input

4: $\mathbf{d}\left[\mathbf{n}\right]$ – const double Input

On entry: x, f and d must be unchanged from the previous call of e01bec.

5: $\mathbf{m}$ – Integer Input

On entry: $m$, the number of points at which the interpolant is to be evaluated.

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

6: $\mathbf{px}\left[\mathbf{m}\right]$ – const double Input

On entry: the $m$ values of $x$ at which the interpolant is to be evaluated.

7: $\mathbf{pf}\left[\mathbf{m}\right]$ – double Output

On exit: $\mathbf{pf}\left[i\right]$ contains the value of the interpolant evaluated at the point $\mathbf{px}\left[\mathit{i}\right]$, for $\mathit{i}=0,1,\dots ,m-1$.

8: $\mathbf{pd}\left[\mathbf{m}\right]$ – double Output

On exit: $\mathbf{pd}\left[\mathit{i}\right]$ contains the first derivative of the interpolant evaluated at the point $\mathbf{px}\left[\mathit{i}\right]$, for $\mathit{i}=0,1,\dots ,m-1$.

9: $\mathbf{fail}$ – 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_INT_ARG_LT

On entry, $\mathbf{m}=⟨\mathit{\text{value}}⟩$.
Constraint: $\mathbf{m}\ge 1$.

On entry, $\mathbf{n}=⟨\mathit{\text{value}}⟩$.
Constraint: $\mathbf{n}\ge 2$.

NE_NOT_MONOTONIC

On entry, $\mathbf{x}\left[r-1\right]\ge \mathbf{x}\left[r\right]$ for $r=⟨\mathit{\text{value}}⟩$ : $\mathbf{x}\left[r-1\right]=⟨\mathit{\text{value}}⟩$, $\mathbf{x}\left[r\right]=⟨\mathit{\text{value}}⟩$.
The values of $\mathbf{x}\left[\mathit{r}\right]$, for $\mathit{r}=0,1,\dots ,n-1$, are not in strictly increasing order.

NW_EXTRAPOLATE

Warning – some points in array px lie outside the range $\mathbf{x}\left[0\right]\dots \mathbf{x}\left[n-1\right]$. Values at these points are unreliable as they have been computed by extrapolation.

7 Accuracy

8 Parallelism and Performance

9 Further Comments

10 Example

10.1 Program Text

10.2 Program Data

10.3 Program Results