pencil.math.Helmholtz
=====================

.. py:module:: pencil.math.Helmholtz

.. autoapi-nested-parse::

   Perform a Helmholtz decomposition on a vector field returning a pair of
   orthogonal vectors with zero divergence and zero curl respectively.



Functions
---------

.. autoapisummary::

   pencil.math.Helmholtz.helmholtz_fft


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

.. py:function:: helmholtz_fft(tot_field, grid, params, nghost=3, pot=True, rot=True, lno_mean=False, nonperi_bc=None, field_scalar=[], s=None, quiet=True)

   helmholz_fft(field, grid, params)

   Creates the decomposition vector pair for the supplied vector field.

   :param tot_field: Vector field of dimension [3, mz, my, mx], which is decomposed.
   :type tot_field: ndarray
   :param grid: Grid object with grid spacing dx, dy, dz.
   :type grid: obj
   :param params: Simulation Params object with domain dimensions Lx, Ly and Lz.
   :type params: obj
   :param nghost: Number of ghost zones to exclude from the fft.
   :type nghost: int
   :param lno_mean: Exclude any mean flow from the decomposition - should drop anyway.
   :type lno_mean: float
   :param nonperi_bc: String if not None with boundary condition label.
                      How to apply the bc needs to be implemented as required.
   :type nonperi_bc: string
   :param field_scalar: Scalar field (density) as debug tool for energy comparison.
   :type field_scalar: ndarray
   :param s: List of three integers if not None for fft dimension.
             If none the dimension of the field [nz,ny,nx] is used.
   :type s: list of int

   :rtype: ndarray with decomposed field.