Driver SCFTCL
=================

Arguments:
  
  * `type` (string) - Type of simulation to perform. Here `"SCFT"` or `"ComplexLangevin"`.

  * `dt` (float) - Timestep used for field relaxations relaxation 
  * `nsteps` (int) - Number of steps to run for
  * `output_freq` (int) - Frequency of outputs to stdout and to scalar files
  * `output_fields_freq` (int) - Frequency of outputs of field files (Default: equal to `output_freq`). Note that writing field files is fairly slow, so less frequent field output will result in better performance.
  * `block_size` (int) - How many timesteps are averaged into a block. See :ref:`Block Averaging` section in Operators documentation.
  * `stop_tolerance` (float) - Error tolerance for SCFT convergence. Run stops when this error is reached (assuming other stopping criteria are met).

  * `field_updater` (string) - Algorithm used to update fields. See :ref:`Field Updaters`. 

  * `variable_cell` (json object) - Optional argument. If defined, then perform variable cell calculation. See :ref:`Variable Cell Formalism`. Requires the following arguments:

    * `lambda` (float) - Lambda relaxation coefficient for cell :math:`\lambda_h`.
    * `stop_tolerance` (float) - Error tolerance for cell shape convergence. Run stops when this error is reached (if all other stopping criteria are met).
    * `update_freq` (int) - Frequency to perform cell updates. Cell is updated every `update_freq` steps.
    * `shape_constraint` (string) - Constraints to apply to the cell shape evolution. Options:

      * `none` - no constraints are placed on cell shape evolution
      * `orthogonal` - only the diagonal of the cell shape tensor is updated. This can be used to force a simulation cell to remain orthogonal during a simulation.
  
  * `resume` (bool) - Whether to resume run from existing operator/field files in the current directory. Useful for restarting/continuing simulations. Default: False.


Example (python) ::

  # for SCFT with variable cell
  fts.driver(dt=5.0,nsteps=5000,output_freq=100,stop_tolerance=1e-05,type='SCFT')
  fts.variable_cell(lambda_=0.1,stop_tolerance=1e-4,update_freq=10,shape_constraint='none')
  fts.field_updater( ... see Field Updaters ... )

  # for Complex Langevin
  fts.driver(type='ComplexLangevin',dt=0.1,nsteps=3000,block_size=100,output_freq=100)

Example (json) ::

  "driver": {
    "dt": 5.0,
    "field_updater": {
      ... see Field Updaters ...
    },

    "nsteps": 4000,
    "output_freq": 100,
    "type": "SCFT",
    "stop_tolerance": 1e-5,
    "variable_cell" :{
      "lambda": 0.1,
      "stop_tolerance": 1e-4,
      "update_freq": 10,
      "shape_constraint": "none"
    }
  },