D02NRF (PDF version)
D02 Chapter Contents
D02 Chapter Introduction
NAG Library Manual

NAG Library Routine Document

D02NRF

Note:  before using this routine, please read the Users' Note for your implementation to check the interpretation of bold italicised terms and other implementation-dependent details.

 Contents

    1  Purpose
    7  Accuracy
    10  Example

1  Purpose

D02NRF is an enquiry routine for communicating with D02NMF or D02NNF when supplying columns of a sparse Jacobian matrix.

2  Specification

SUBROUTINE D02NRF ( J, IPLACE, INFORM)
INTEGER  J, IPLACE, INFORM(23)

3  Description

D02NRF is required when D02NMF or D02NNF is being used with sparse matrix linear algebra. After an exit from D02NMF or D02NNF with IREVCM=8, D02NRF must be called to determine which column of the Jacobian is required and where it is to be placed in the array RWORK (a argument of D02NMF or D02NNF).

4  References

See the D02M–N Sub-chapter Introduction.

5  Arguments

1:     J – INTEGEROutput
On exit: the index j of the column of the Jacobian which is required.
2:     IPLACE – INTEGEROutput
On exit: indicates which locations in the array RWORK to fill with the jth column.
If IPLACE=1, the i,jth element of the Jacobian must be placed in RWORK50+2×LDYSAV+i, otherwise the i,jth element must be placed in RWORK50+LDYSAV+i.
If JCEVAL='F', in the previous call to D02NUF, then IPLACE=2 always, hence the jth column of the Jacobian must be placed in RWORK50+LDYSAV+i, for i=1,2,,NEQ.
RWORK, NEQ and LDYSAV are arguments of D02NMF and D02NNF.
3:     INFORM23 – INTEGER arrayCommunication Array
On entry: contains information supplied by the integrator.

6  Error Indicators and Warnings

None.

7  Accuracy

Not applicable.

8  Parallelism and Performance

D02NRF is not threaded in any implementation.

9  Further Comments

None.

10  Example

See Section 10 in D02NNF.

D02NRF (PDF version)
D02 Chapter Contents
D02 Chapter Introduction
NAG Library Manual

© The Numerical Algorithms Group Ltd, Oxford, UK. 2016