Plot Templates

pyrolite includes some ready-made templates for well-known plots. These can be used to create new plots, or add a template to an existing matplotlib.axes.Axes.

import matplotlib.pyplot as plt

Bivariate Templates

First let’s build a simple total-alkali vs silica ( TAS()) diagram:

from pyrolite.plot.templates import TAS, SpinelFeBivariate
from pyrolite.util.plot.axes import share_axes

ax = TAS(linewidth=0.5, add_labels=True)
plt.show()

A few different variants are now available, with slightly different positioning of field boundaries, and with some fields combined:

fig, ax = plt.subplots(1, 3, figsize=(12, 3))

TAS(ax=ax[0], linewidth=0.5, add_labels=True, which_model=None)  # Middlemost's TAS
TAS(ax=ax[1], linewidth=0.5, add_labels=True, which_model="LeMaitre")  # LeMaitre's TAS
TAS(ax=ax[2], linewidth=0.5, add_labels=True, which_model="LeMaitreCombined")

for a in ax[1:]:
    a.set(yticks=[], ylabel=None)

For distinguishing Fe-rich variants of spinel phases, the bivariate spinel diagram can be useful:

ax = SpinelFeBivariate(linewidth=0.5, add_labels=True)
plt.show()

/home/docs/checkouts/readthedocs.org/user_builds/pyrolite/checkouts/main/pyrolite/util/plot/axes.py:219: RuntimeWarning: More than 20 figures have been opened. Figures created through the pyplot interface (`matplotlib.pyplot.figure`) are retained until explicitly closed and may consume too much memory. (To control this warning, see the rcParam `figure.max_open_warning`). Consider using `matplotlib.pyplot.close()`.
  fig, ax = plt.subplots(1, **subkwargs(kwargs, plt.subplots, plt.figure))

pyrolite contains templates for the Pearce diagrams, used to discriminate mafic rocks (and particularly basalts) based on their whole-rock geochemistry. Two templates are included: pearceThNbYb() and pearceTiNbYb(). We can create some axes and add these templates to them:

from pyrolite.plot.templates import pearceThNbYb, pearceTiNbYb

fig, ax = plt.subplots(1, 2, figsize=(10, 4))
share_axes(ax, which="x")  # these diagrams have the same x axis

pearceThNbYb(ax=ax[0])
pearceTiNbYb(ax=ax[1])

plt.tight_layout()  # nicer spacing for axis labels

pyrolite also now includes some diagram templates for discrimination of sandstones based on their whole-rock geochemistry (Pettijohn(), Herron()):

from pyrolite.plot.templates import Herron, Pettijohn

fig, ax = plt.subplots(1, 2, figsize=(10, 4))
share_axes(ax, which="x")  # these diagrams have the same x axis

Pettijohn(ax=ax[0], add_labels=True)
Herron(ax=ax[1], add_labels=True)

plt.tight_layout()

Ternary Templates

pyrolite now also includes ternary classification diagrams inlcuding the QAP() and USDASoilTexture() diagrams:

from pyrolite.plot.templates import (
    QAP,
    FeldsparTernary,
    JensenPlot,
    SpinelTrivalentTernary,
    USDASoilTexture,
)

ax = QAP(linewidth=0.4)
plt.show()

ax = USDASoilTexture(linewidth=0.4)
plt.show()

For the feldspar ternary diagram, which is complicated by a miscibility gap, there are two modes: ‘default’ and ‘miscibility-gap’. The second of these provides a simplified approximation of the miscibility gap between k-feldspar and plagioclase, wheras ‘default’ ignores this aspect (which itself is complicated by temperature):

fig, ax = plt.subplots(1, 2, figsize=(12, 6))
FeldsparTernary(ax=ax[0], linewidth=0.4, add_labels=True, mode="default")
FeldsparTernary(ax=ax[1], linewidth=0.4, add_labels=True, mode="miscibility-gap")
plt.tight_layout()
plt.show()

For general spinel phase discrimination, a ternary classification diagram can be used to give labels based on trivalent cationic content (\(\mathrm{Cr^{3+}}\), \(\mathrm{Al^{3+}}\), \(\mathrm{Fe^{3+}}\)):

SpinelTrivalentTernary(linewidth=0.4, add_labels=True, figsize=(6, 6))
plt.show()

The Jensen plot is another cationic ternary discrimination diagram (Jensen, 1976), for subalkaline volcanic rocks:

JensenPlot(linewidth=0.4, add_labels=True, figsize=(7, 7))
plt.show()

References and other notes for diagram templates can be found within the docstrings and within the pyrolite documentation:

help(TAS)

Help on function TAS in module pyrolite.plot.templates.TAS:

TAS(ax=None, add_labels=False, which_labels='ID', relim=True, color='k', which_model=None, **kwargs)
    Adds the TAS diagram to an axes. Diagram from Middlemost (1994) [#pyrolite.plot.templates.TAS.TAS_1]_,
    a closed-polygon variant after Le Bas et al (1992) [#pyrolite.plot.templates.TAS.TAS_2]_.

    Parameters
    ----------
    ax : :class:`matplotlib.axes.Axes`
        Axes to add the template on to.
    add_labels : :class:`bool`
        Whether to add labels at polygon centroids.
    which_labels : :class:`str`
        Which labels to add to the polygons (e.g. for TAS, 'volcanic', 'intrusive'
        or the field 'ID').
    relim : :class:`bool`
        Whether to relimit axes to fit the built in ranges for this diagram.
    color : :class:`str`
        Line color for the diagram.
    which_model : :class:`str`
        The name of the model variant to use, if not Middlemost.

    Returns
    -------
    ax : :class:`matplotlib.axes.Axes`

    References
    -----------
    .. [#pyrolite.plot.templates.TAS.TAS_1] Middlemost, E. A. K. (1994).
                Naming materials in the magma/igneous rock system.
                Earth-Science Reviews, 37(3), 215–224.
                doi: `10.1016/0012-8252(94)90029-9 <https://dx.doi.org/10.1016/0012-8252(94)90029-9>`__

    .. [#pyrolite.plot.templates.TAS.TAS_2] Le Bas, M.J., Le Maitre, R.W., Woolley, A.R. (1992).
                The construction of the Total Alkali-Silica chemical
                classification of volcanic rocks.
                Mineralogy and Petrology 46, 1–22.
                doi: `10.1007/BF01160698 <https://dx.doi.org/10.1007/BF01160698>`__