Kevin,
The manual page is misleading. It actually returns the total length of the
history as set by KSPSetResidualHistory(), not the number of iterations.
Barry
> On Jan 10, 2024, at 7:09 PM, Kevin G. Wang <[email protected]> wrote:
>
> Hello everyone!
>
> I am writing a code that uses PETSc/KSP to solve linear systems. I just
> realized that after running "KSPSolve(...)", the number of iterations given
> by
>
> KSPGetIterationNumber(ksp, &numIts)
>
> is *different* from the size of the residual history given by
>
> KSPGetResidualHistory(ksp, NULL, &nEntries);
>
> That is, "numIts" is not equal to "nEntries". Is this expected, or a bug in
> my code? (I thought they should be the same...)
>
> I have tried several pairs of solvers and preconditioners (e.g., fgmres &
> bjacobi, ibcgs & bjacobi). This issue happens to all of them.
>
> Thanks!
> Kevin
>
> --
> Kevin G. Wang, Ph.D.
> Associate Professor
> Kevin T. Crofton Department of Aerospace and Ocean Engineering
> Virginia Tech
> 1600 Innovation Dr., VTSS Rm 224H, Blacksburg, VA 24061
> Office: (540) 231-7547 | Mobile: (650) 862-2663
> URL: https://www.aoe.vt.edu/people/faculty/wang.html
> Codes: https://github.com/kevinwgy
