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vova New Member Offline Posts: 3	Sparse matrix Apr 04^th, 2003, 4:00pm I am using Sparse V1.3a and need to get a pointer to an existing element knowing only row and column numbers. Actually Sparse which I am using does not have a function for that. So I just want to know if such a function already exist, or I am forced to write my own, modifing spPrint()? Thanks, Vova.
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Ken Kundert Global Moderator Offline Posts: 2384 Silicon Valley	Re: Sparse matrix Reply #1 - Apr 4^th, 2003, 4:17pm The function spGetElement allows you to get a pointer to an existing element knowing only the row and column number. It will, however, create the element if it does not already exist. -Ken
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vova New Member Offline Posts: 3	Re: Sparse matrix Reply #2 - Apr 4^th, 2003, 5:06pm I don't want to waste memory. I have a look at spGetElement. It seems I can use spcFindElementinCol() with NO as a last argumen. But I am cunfused, will it work for col=row? Thanks a lot, Vova.
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Ken Kundert Global Moderator Offline Posts: 2384 Silicon Valley	Re: Sparse matrix Reply #3 - Apr 8^th, 2003, 3:24pm There is a function in the Spice3 compatibility code in spSMP.c that does what you want. It is SMPfindElt(). Do you have that code? -Ken
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vova New Member Offline Posts: 3	Re: Sparse matrix Reply #4 - Apr 10^th, 2003, 1:55pm Yes, I have spsmp.c. Thanks for letting me know about SMPfindElt(), now I am using this function. Vova.
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rf-design

Senior Member

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Reiner Franke

Posts: 165
Germany

Re: Sparse matrix
Reply #5 - Oct 13^th, 2003, 2:06am

I am interessted in circuit simulation implementation.

Does anybody now about

1. Solving sparse matrix by combinations of direct and iterative method. Where pivot ordering and selection generate side information which part to solve direct and which iterative.

2. Is there a reuse of pivot information while processing different transient steps?

3. Does the pivot selection and reordering change much at circuit discontiniousities?

4. Does circuit simulator implementations exist based on state variable approach. How these implement rank deficiencies?

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