NAG Library Routine Document

d02nrf (ivp_stiff_sparjac_enq)

1

Purpose

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Specification

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Description

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References

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Arguments

1:     $\mathbf{j}$ – IntegerOutput

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

2:     $\mathbf{iplace}$ – 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, $\mathbf{iplace}=2$ 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 arrayCommunication Array

On entry: contains information supplied by the integrator.

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Error Indicators and Warnings

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Accuracy

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Parallelism and Performance

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Further Comments

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Example