[petsc-users] Question about ts_ssp

[Sean Farley]

>
> Methods can be chosen with -ts_ssp_type {rks2,rks3,rk104}
>
> rks2: Second order methods with any number s>1 of stages. c_eff = (s-1)/s
>
> rks3: Third order methods with s=n^2 stages, n>1. c_eff = (s-n)/s
>
> rk104: A 10-stage fourth order method. c_eff = 0.6
>

This means that there there are only three options for -ts_ssp_type. Namely,

-ts_ssp_type rks2
-ts_ssp_type rks3
-ts_ssp_type rk104

>  However, when I write
>
>  -ts_ssp_type rk53
>

Therefore, this is not even close to being valid. What are you trying to do?
Get 5 work stages? You can see other ssp options with the -h option
(probably helps to pipe the output to 'grep'),

./program -ts_type ssp -h | grep ssp
  -ts_type <beuler>: TS method (one of) euler beuler cn pseudo gl ssp theta
alpha
  -ts_ssp_type <rk104>: Type of SSP method (one of) rks2 rks3 rk104
(TSSSPSetType)
  -ts_ssp_nstages <5>: Number of stages (TSSSPSetNumStages)

So, you would probably want the following options,

./program -ts_type ssp -ts_ssp_type rks3 -ts_ssp_nstages 5

but keep in mind that 5 is the default for -ts_ssp_nstages.

Hope that helps.

Sean
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