# Flexible GMRES (fgmres) **URL:** \ **Category:** General Discussion\ **Created:** [November 15, 2023, 4:43pm UTC](https://community.freefem.org/t/flexible-gmres-fgmres/2804 "2023-11-15T16:43:58Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Talal](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Talal](https://community.freefem.org/u/Talal)\ **Post date:** [November 15, 2023, 4:43pm UTC](https://community.freefem.org/t/flexible-gmres-fgmres/2804/1 "2023-11-15T16:43:58Z")
I’m utilizing fGMRES and require guidance on how to implement the restart number. ---
**Author:** ![prj](https://avatars.discourse-cdn.com/v4/letter/p/ecae2f/32.png) [@prj](https://community.freefem.org/u/prj)\ **Post date:** [November 15, 2023, 4:46pm UTC](https://community.freefem.org/t/flexible-gmres-fgmres/2804/2 "2023-11-15T16:46:24Z")
`-ksp_gmres_restart XYZ`? ---
**Author:** ![Talal](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Talal](https://community.freefem.org/u/Talal)\ **Post date:** [November 26, 2023, 7:42pm UTC](https://community.freefem.org/t/flexible-gmres-fgmres/2804/3 "2023-11-26T19:42:49Z")
Would you kindly provide me with examples relevant to my case, such as the Navier-Stokes or Stokes equations using “-ksp\_gmres\_restart”? Additionally, I’m currently working with splitting the solution of the linear system into three variables (u, ksi, p) in order to calculate erroru, errorksi, and errorp. I need to use the fieldsplit preconditioner to split the linear system. If possible, please provide examples if you have it to support my case. Thank you. ---
**Author:** ![prj](https://avatars.discourse-cdn.com/v4/letter/p/ecae2f/32.png) [@prj](https://community.freefem.org/u/prj)\ **Post date:** [November 26, 2023, 7:43pm UTC](https://community.freefem.org/t/flexible-gmres-fgmres/2804/4 "2023-11-26T19:43:56Z")
There are many examples in [https://github.com/FreeFem/FreeFem-sources/tree/master/examples/hpddm](https://github.com/FreeFem/FreeFem-sources/tree/master/examples/hpddm).