NAG FL Interface
d02nrf (ivp_​stiff_​sparjac_​enq)

1 Purpose

2 Specification

3 Description

4 References

5 Arguments

1: $\mathbf{j}$ – Integer Output

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

2: $\mathbf{iplace}$ – Integer Output

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, $\mathbf{iplace}=2$ 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 arguments of d02nmf and d02nnf.

3: $\mathbf{inform}\left(23\right)$ – Integer array Communication 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