mplstereonet provides lower-hemisphere equal-area and equal-angle stereonets
for matplotlib.
.. image:: http://joferkington.github.io/mplstereonet/images/equal_area_equal_angle_comparison.png :alt: Comparison of equal angle and equal area stereonets. :align: center :target: https://github.com/joferkington/mplstereonet/blob/master/examples/equal_area_equal_angle_comparison.py
mplstereonet can be installed from PyPi using pip by::
pip install mplstereonetAlternatively, you can download the source and install locally using (from the main directory of the repository)::
python setup.py installIf you're planning on developing mplstereonet or would like to experiment
with making local changes, consider setting up a development installation so
that your changes are reflected when you import the package::
python setup.py developIn most cases, you'll want to import mplstereonet and then make an axes
with projection="stereonet" (By default, this is an equal-area stereonet).
Alternately, you can use mplstereonet.subplots, which functions identically
to matplotlib.pyplot.subplots, but creates stereonet axes.
As an example::
import matplotlib.pyplot as plt
import mplstereonet
fig = plt.figure()
ax = fig.add_subplot(111, projection='stereonet')
strike, dip = 315, 30
ax.plane(strike, dip, 'g-', linewidth=2)
ax.pole(strike, dip, 'g^', markersize=18)
ax.rake(strike, dip, -25)
ax.grid()
plt.show().. image:: http://joferkington.github.io/mplstereonet/images/basic.png :alt: A basic stereonet with a plane, pole to the plane, and rake along the plane :align: center :target: https://github.com/joferkington/mplstereonet/blob/master/examples/basic.py
Planes, lines, poles, and rakes can be plotted using axes methods (e.g.
ax.line(plunge, bearing) or ax.rake(strike, dip, rake_angle)).
All planar measurements are expected to follow the right-hand-rule to indicate dip direction. As an example, 315/30S would be 135/30 following the right-hand rule.
mplstereonet also provides a few different methods of producing contoured
orientation density diagrams.
The ax.density_contour and ax.density_contourf axes methods provide density
contour lines and filled density contours, respectively. "Raw" density grids
can be produced with the mplstereonet.density_grid function.
As a basic example::
import matplotlib.pyplot as plt
import numpy as np
import mplstereonet
fig, ax = mplstereonet.subplots()
strike, dip = 90, 80
num = 10
strikes = strike + 10 * np.random.randn(num)
dips = dip + 10 * np.random.randn(num)
cax = ax.density_contourf(strikes, dips, measurement='poles')
ax.pole(strikes, dips)
ax.grid(True)
fig.colorbar(cax)
plt.show().. image:: http://joferkington.github.io/mplstereonet/images/contouring.png :alt: Orientation density contours. :align: center :target: https://github.com/joferkington/mplstereonet/blob/master/examples/contouring.py
By default, a modified Kamb method with exponential smoothing [Vollmer1995] is
used to estimate the orientation density distribution. Other methods (such as
the "traditional" Kamb [Kamb1956] and "Schmidt" (a.k.a. 1%) methods) are
available as well. The method and expected count (in standard deviations) can
be controlled by the method and sigma keyword arguments, respectively.
.. image:: http://joferkington.github.io/mplstereonet/images/contour_angelier_data.png :alt: Orientation density contours. :align: center :target: https://github.com/joferkington/mplstereonet/blob/master/examples/contour_angelier_data.py
mplstereonet also includes a number of utilities to parse structural
measurements in either quadrant or azimuth form such that they follow the
right-hand-rule.
For an example, see parsingexample.py::
Parse quadrant azimuth measurements
"N30E" --> 30.0
"E30N" --> 60.0
"W10S" --> 260.0
"N 10 W" --> 350.0
Parse quadrant strike/dip measurements.
Note that the output follows the right-hand-rule.
"215/10" --> Strike: 215.0, Dip: 10.0
"215/10E" --> Strike: 35.0, Dip: 10.0
"215/10NW" --> Strike: 215.0, Dip: 10.0
"N30E/45NW" --> Strike: 210.0, Dip: 45.0
"E10N 20 N" --> Strike: 260.0, Dip: 20.0
"W30N/46.7 S" --> Strike: 120.0, Dip: 46.7
Similarly, you can parse rake measurements that don't follow the RHR.
"N30E/45NW 10NE" --> Strike: 210.0, Dip: 45.0, Rake: 170.0
"210 45 30N" --> Strike: 210.0, Dip: 45.0, Rake: 150.0
"N30E/45NW raking 10SW" --> Strike: 210.0, Dip: 45.0, Rake: 10.0Additionally, you can find plane intersections and make other calculations by combining utility functions. See planeintersection.py and parse_anglierdata.py for examples.
mplstereonet contains orientation data analysis methods, as well as
plotting functionality. For example, you can fit planes to girdles <https://mplstereonet.readthedocs.io/en/latest/examples/fit_girdle_example.html>_
or fit a pole to points <https://mplstereonet.readthedocs.io/en/latest/mplstereonet.html#mplstereonet.fit_pole>_,
identify different modes of conjugate sets of faults <https://mplstereonet.readthedocs.io/en/latest/examples/kmeans_example.html>,
or calculate flattening values for Flinn plots <https://mplstereonet.readthedocs.io/en/latest/mplstereonet.html#mplstereonet.eigenvectors>.
Full documentation is available at https://mplstereonet.readthedocs.io/en/latest/mplstereonet.html
.. [Kamb1956] Kamb, 1959. Ice Petrofabric Observations from Blue Glacier, Washington, in Relation to Theory and Experiment. Journal of Geophysical Research, Vol. 64, No. 11, pp. 1891--1909.
.. [Vollmer1995] Vollmer, 1995. C Program for Automatic Contouring of Spherical Orientation Data Using a Modified Kamb Method. Computers & Geosciences, Vol. 21, No. 1, pp. 31--49.
.. _parsing_example.py: https://mplstereonet.readthedocs.io/en/latest/examples/parsing_example.html
.. _plane_intersection.py: https://mplstereonet.readthedocs.io/en/latest/examples/plane_intersection.html
.. _parse_anglier_data.py: https://mplstereonet.readthedocs.io/en/latest/examples/parse_angelier_data.html