NAG Library Routine Document

d02nxf  (ivp_stiff_sparjac_diag)

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Purpose

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Specification

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Description

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References

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Arguments

1:     $\mathbf{icall}$ – IntegerInput

On entry: indicates whether or not all output arguments have been set during the call to the integrator. If so, that is, if the integrator returned with $\mathbf{ifail}=\mathbf{0}$ or $\mathbf{12}$, then icall must be set to $0$. Otherwise icall must be set to $1$, indicating that integration did not take place due to lack of space in arrays wkjac and jacpvt, and only liwreq, liwusd, lrwreq, lrwusd have been set.

2:     $\mathbf{liwreq}$ – IntegerOutput

On exit: the length of the integer workspace jacpvt reserved for the sparse matrix routines.

3:     $\mathbf{liwusd}$ – IntegerOutput

On exit: the length of the integer workspace jacpvt actually used by the sparse matrix routines.

4:     $\mathbf{lrwreq}$ – IntegerOutput

On exit: the length of the real workspace wkjac reserved for the sparse matrix routines.

5:     $\mathbf{lrwusd}$ – IntegerOutput

On exit: the length of the real workspace wkjac actually used by the sparse matrix routines.

6:     $\mathbf{nlu}$ – IntegerOutput

On exit: the number of $LU$ decompositions done during the integration.

7:     $\mathbf{nnz}$ – IntegerOutput

On exit: the number of nonzeros in the Jacobian.

8:     $\mathbf{ngp}$ – IntegerOutput

On exit: the number of fcn or resid calls needed to form the Jacobian.

9:     $\mathbf{isplit}$ – IntegerOutput

On exit: an appropriate value for the argument isplit when calling d02nuf for subsequent runs of similar problems.

10:   $\mathbf{igrow}$ – IntegerOutput

On exit: an estimate of the growth of the elements encountered during the last $LU$ decomposition performed. If the actual estimate exceeds the largest possible integer value for the machine being used (see x02bbf) igrow is set to the value returned by x02bbf.

11:   $\mathbf{lblock}$ – LogicalInput

On entry: the value used for the argument lblock when calling d02nuf.

12:   $\mathbf{nblock}$ – IntegerOutput

On exit: if $\mathbf{lblock}=\mathrm{.TRUE.}$, nblock contains the number of diagonal blocks in the Jacobian matrix permuted to block lower triangular form. If $\mathbf{nblock}=1$ then on subsequent runs of a similar problem lblock should be set to .FALSE. in the call to d02nuf.

If $\mathbf{lblock}=\mathrm{.FALSE.}$, $\mathbf{nblock}=1$.

13:   $\mathbf{inform}\left(23\right)$ – 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