streamtracer

streamtracer is a Python package for rapid streamline tracing on regularly spaced grids. The actual streamline tracing is done at a low level in Rust, with a nice Python API provided on top.

• streamtracer Package
• Release History

Installing

It is possible to install streamtracer in one go with:

pip install streamtracer

or using conda with:

conda install -c conda-forge streamtracer

There are wheels available for Linux, macOS and Windows. If you need to compile from source, you will need to have a Rust compiler installed.

If you have problems installing, please open an issue at sunpy/streamtracer#issues

Usage

To use, create a streamtracer.StreamTracer object

import numpy as np
from streamtracer import StreamTracer, VectorGrid

nsteps = 10000
step_size = 0.1
tracer = StreamTracer(nsteps, step_size)

and a streamtracer.VectorGrid

field = np.ones((10, 10, 10, 3))
grid_spacing = [1, 2, 1]
grid = VectorGrid(field, grid_spacing)

This can then be used to trace lines through a 3D cartesian vector field

seeds = np.array([[0, 0, 0], [0, 0, 1]])
tracer.trace(seeds, grid)

and the traced field lines can be accessed via. the .xs attribute

print(f'Number of traced lines: {len(tracer.xs)}')
line_lengths = [len(x) for x in tracer.xs]
print(f'Line lengths: {line_lengths}')

Number of traced lines: 2
Line lengths: [156, 139]

For more information see the streamtracer API docs.

Boundary handling

When the stream tracer steps outside the boundary of the grid, the first point outside the grid is saved in the traced stream line.