pencil.calc.streamlines
=======================

.. py:module:: pencil.calc.streamlines

.. autoapi-nested-parse::

   Traces streamlines of a vector field from z0 to z1, similar to
   'streamlines.f90'.



Classes
-------

.. autoapisummary::

   pencil.calc.streamlines.Stream


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

.. py:class:: Stream(field, params, xx=(0, 0, 0), time=(0, 1), metric=None, splines=None)

   Bases: :py:obj:`object`


   Contains the methods and results for the streamline tracing for a field on a grid.

   Trace a field starting from xx in any rectilinear coordinate system
   with constant dx, dy and dz and with a given metric.

   call signature:

     tracer(field, params, xx=[0, 0, 0], time=[0, 1], metric=None, splines=None):

   Keyword arguments:

   *field*:
     Vector field which is integrated over with shape [n_vars, nz, ny, nx].
     Its elements are the components of the field using unnormed
     unit-coordinate vectors.

   *params*:
     Simulation and tracer parameters.

   *xx*:
     Starting point of the field line integration with starting time.

   *time*:
       Time array for which the tracer is computed.

   *metric*:
       Metric function that takes a point [x, y, z] and an array
       of shape [3, 3] that has the comkponents g_ij.
       Use 'None' for Cartesian metric.

   *splines*:
       Pre-computed spline coefficients for tricubic interpolation.
       This can speed up the calculations greatly for repeated streamline
       tracing on the same data. Should be computed using scipy.ndimage.spline_filter
       with order=3 for each vector component, i.e.:
           splines = np.array([spline_filter(field[0], order=3),
                               spline_filter(field[1], order=3),
                               spline_filter(field[2], order=3)])


   .. py:attribute:: params


   .. py:attribute:: xx
      :value: (0, 0, 0)



   .. py:attribute:: time
      :value: (0, 1)



   .. py:attribute:: section_l


   .. py:attribute:: total_l


   .. py:attribute:: iterations


   .. py:attribute:: section_dh


   .. py:attribute:: total_h
      :value: 1