NAG Library Routine Document

D02NRF

1  Purpose

2  Specification

3  Description

4  References

5  Parameters

1:     $\mathrm{J}$ – INTEGEROutput

On exit: the index $j$ of the column of the Jacobian which is required.

2:     $\mathrm{IPLACE}$ – INTEGEROutput

On exit: indicates which locations in the array RWORK to fill with the $j$th column.

If $\mathbf{IPLACE}=1$, the $\left(i,j\right)$th element of the Jacobian must be placed in $\mathbf{RWORK}\left(50+2\times \mathbf{LDYSAV}+i\right)$, otherwise the $\left(i,j\right)$th element must be placed in $\mathbf{RWORK}\left(50+\mathbf{LDYSAV}+i\right)$.

If $\mathbf{JCEVAL}=\text{'F'}$, in the previous call to D02NUF, then $\mathbf{IPLACE}=2$ always, hence the $j$th column of the Jacobian must be placed in $\mathbf{RWORK}\left(50+\mathbf{LDYSAV}+\mathit{i}\right)$, for $\mathit{i}=1,2,\dots ,\mathbf{NEQ}$.

RWORK, NEQ and LDYSAV are parameters of D02NMF and D02NNF.

3:     $\mathrm{INFORM}\left(23\right)$ – INTEGER arrayCommunication Array

On entry: contains information supplied by the integrator.

6  Error Indicators and Warnings

7  Accuracy

8  Parallelism and Performance

9  Further Comments

10  Example