dedalus.extras.flow_tools
=========================

.. py:module:: dedalus.extras.flow_tools

.. autoapi-nested-parse::

   Extra tools that are useful in hydrodynamical problems.







Module Contents
---------------

.. py:class:: CFL(solver, initial_dt, cadence=1, safety=1.0, max_dt=np.inf, min_dt=0.0, max_change=np.inf, min_change=0.0, threshold=0.0)

   Computes CFL-limited timestep from a set of frequencies/velocities.

   :Parameters: * **solver** (*solver object*) -- Problem solver
                * **initial_dt** (*float*) -- Initial timestep
                * **cadence** (*int, optional*) -- Iteration cadence for computing new timestep (default: 1)
                * **safety** (*float, optional*) -- Safety factor for scaling computed timestep (default: 1.)
                * **max_dt** (*float, optional*) -- Maximum allowable timestep (default: inf)
                * **min_dt** (*float, optional*) -- Minimum allowable timestep (default: 0.)
                * **max_change** (*float, optional*) -- Maximum fractional change between timesteps (default: inf)
                * **min_change** (*float, optional*) -- Minimum fractional change between timesteps (default: 0.)
                * **threshold** (*float, optional*) -- Fractional change threshold for changing timestep (default: 0.)

   .. rubric:: Notes

   The new timestep is computed by summing across the provided frequencies
   for each grid point, and then reciprocating the maximum "total" frequency
   from the entire grid.


   .. py:method:: add_frequency(freq)

      Add an on-grid frequency.



   .. py:method:: add_velocity(velocity)

      Add grid-crossing frequency from a velocity vector.

      :Parameters: **velocity** (*field object*) -- The velocity; must be a vector with a tensorsig of length 1



   .. py:method:: compute_dt()


   .. py:method:: compute_timestep()

      Compute CFL-limited timestep.



   .. py:attribute:: cadence
      :value: 1



   .. py:attribute:: frequencies


   .. py:attribute:: max_change


   .. py:attribute:: max_dt


   .. py:attribute:: min_change
      :value: 0.0



   .. py:attribute:: min_dt
      :value: 0.0



   .. py:attribute:: reducer


   .. py:attribute:: safety
      :value: 1.0



   .. py:attribute:: solver


   .. py:attribute:: stored_dt


   .. py:attribute:: threshold
      :value: 0.0



.. py:class:: GlobalArrayReducer(comm, dtype=np.float64)

   Directs parallelized reduction of distributed array data.

   :Parameters: * **comm** (*MPI communicator*) -- MPI communicator
                * **dtype** (*data type, optional*) -- Array data type (default: np.float64)


   .. py:method:: global_max(data, empty=-np.inf)

      Compute global max of all array data.



   .. py:method:: global_mean(data)

      Compute global mean of all array data.



   .. py:method:: global_min(data, empty=np.inf)

      Compute global min of all array data.



   .. py:method:: reduce_scalar(local_scalar, mpi_reduce_op)

      Compute global reduction of a scalar from each process.



   .. py:attribute:: comm


.. py:class:: GlobalFlowProperty(solver, cadence=1)

   Directs parallelized determination of a global flow property on the grid.

   :Parameters: * **solver** (*solver object*) -- Problem solver
                * **cadence** (*int, optional*) -- Iteration cadence for property evaluation (default: 1)

   .. rubric:: Examples

   >>> flow = GlobalFlowProperty(solver)
   >>> flow.add_property('sqrt(u*u + w*w) * Lz / nu', name='Re')
   ...
   >>> flow.max('Re')
   1024.5


   .. py:method:: add_property(property, name, precompute_integral=False)

      Add a property.



   .. py:method:: grid_average(name)

      Compute global mean of a property on the grid.



   .. py:method:: max(name)

      Compute global max of a property on the grid.



   .. py:method:: min(name)

      Compute global min of a property on the grid.



   .. py:method:: volume_average(name)
      :abstractmethod:


      Compute volume average of a property.



   .. py:method:: volume_integral(name)

      Compute volume integral of a property.



   .. py:attribute:: cadence
      :value: 1



   .. py:attribute:: properties


   .. py:attribute:: reducer


   .. py:attribute:: solver


.. py:data:: logger