eigval Module

Does the related namelist exist in the target input file?

Used to hold the specific index of numbered namelists

Do we want to skip the read step in init?

Do we want to skip the broadcast step in init?

Do we want to skip the smaart defaults in init?

Determines which operator SLEPc is finding eigenvalues of. If .false. then SLEPc analyses the time advance operator, so internally works with the eigenvalue exp(-i*omega*nadv*dt). If .true. then SLEPc analyses a time derivative operator, so internally works with the eigenvalue -i*omega. Note we form a first order one sided approximation of the time derivative (e.g. (g_{n+nadv}-g_{n})/(nadv*code_dt)) to be analysed.

Sets the extraction technique, must be one of:

Sets the maximum number of SLEPC iterations used. If not set (recommended) then let SLEPC decide what to use (varies with different options).

The number of eigenmodes to search for. The actual number of modes found may be larger than this.

How many GS2 timesteps to take each time SLEPc wants to advance the distribution function. Useful to separate closely spaced eigenvalues without changing delt.

If true then we save a set of restart files for each eigenmode found. These are named as the standard restart file (i.e. influenced by the restart_file input), but have eig_<id> appended near the end, where <id> is an integer representing the eigenmode id. If save_distfn of gs2_diagnostics_knobs is true then will also save the distribution function files.

Sets the type of solver to use, must be one of:

Imaginary part of the eigenvalue target. Often beneficial to set this fairly large (e.g. 10) when looking for unstable modes. Used with the target_* which_option mode.

Real part of the eigenvalue target. Often beneficial to set this fairly small (e.g. ~0). Used with the target_* which_option mode.

Sets tolerance on SLEPC eigenmode search. Used to determine when an eigenmode has been found. Note this is the tolerance based on the SLEPc eigenvalue, which is the time advance eigenvalue $\exp{\left(-i\Omega\textrm{nadv delt}\right)}$ rather than the GS2 eigenvalue, $\Omega$.

Sets the type of spectral transform to be used. This can help extract interior eigenvalues. Must be one of

If true then provide an initial guess for the eigenmode based on using init_g routines to initialise g. Can be helpful in accelerating initial phase of eigensolver. Can also be quite useful with ginit_option='many' (etc.) to start an eigenvalue search from a previously obtained solution, allowing both eigenmode refinement and sub-dominant mode detection.

Sets SLEPC mode of operation (i.e. what sort of eigenvalues it looks for). Note that this refers to the SLEPc eigenvalue, i.e. the time advance eigenvalue $\exp{\left(-i\Omega\textrm{nadv delt}\right)}$. In other words one should select 'largest_real' to search for modes with the largest growth rate. Must be one of