Fixing C2v, adding stereographic plots for every point group, and making SYmmetry match ITOC standards

doc/tutorials/clustering_misorientations.ipynb

@@ -43,7 +43,6 @@
     "from orix.quaternion.symmetry import D6\n",
     "from orix.vector import Vector3d\n",
     "\n",
-    "\n",
     "plt.rcParams.update({\"font.size\": 20, \"figure.figsize\": (10, 10)})\n",
     "\n",
     "register_projections()"

doc/tutorials/clustering_orientations.ipynb

@@ -46,7 +46,6 @@
     "from orix.quaternion.symmetry import D6\n",
     "from orix.vector import AxAngle, Vector3d\n",
     "\n",
-    "\n",
     "plt.rcParams.update(\n",
     "    {\"font.size\": 20, \"figure.figsize\": (10, 10), \"figure.facecolor\": \"w\"}\n",
     ")"

doc/tutorials/crystal_directions.ipynb

@@ -42,7 +42,6 @@
     "from orix.quaternion import Orientation, Rotation, symmetry\n",
     "from orix.vector import Miller, Vector3d\n",
     "\n",
-    "\n",
     "plt.rcParams.update(\n",
     "    {\n",
     "        \"figure.figsize\": (7, 7),\n",

doc/tutorials/crystal_map.ipynb

@@ -44,7 +44,6 @@
     "from orix.quaternion import Orientation, Rotation, symmetry\n",
     "from orix.vector import Vector3d\n",
     "\n",
-    "\n",
     "plt.rcParams.update({\"figure.figsize\": (7, 7), \"font.size\": 15})\n",
     "tempdir = tempfile.mkdtemp() + \"/\""
    ]

doc/tutorials/inverse_pole_figures.ipynb

@@ -61,7 +61,6 @@
     "from orix.quaternion import Orientation, symmetry\n",
     "from orix.vector import Vector3d\n",
     "\n",
-    "\n",
     "# We'll want our plots to look a bit larger than the default size\n",
     "new_params = {\n",
     "    \"figure.facecolor\": \"w\",\n",

doc/tutorials/point_groups.ipynb

@@ -37,7 +37,6 @@
     "from orix.quaternion import Rotation, symmetry\n",
     "from orix.vector import Vector3d\n",
     "\n",
-    "\n",
     "plt.rcParams.update({\"font.size\": 15})"
    ]
   },

doc/tutorials/s2_sampling.ipynb

@@ -38,7 +38,6 @@
     "from orix.quaternion import symmetry\n",
     "from orix.sampling import sample_S2_methods, sample_S2\n",
     "\n",
-    "\n",
     "plt.rcParams.update({\"font.size\": 20, \"lines.markersize\": 2})"
    ]
   },

doc/tutorials/stereographic_projection.ipynb

@@ -47,7 +47,6 @@
     "from orix import plot  # Register orix' projections with Matplotlib\n",
     "from orix.vector import Vector3d\n",
     "\n",
-    "\n",
     "# We'll want our plots to look a bit larger than the default size\n",
     "plt.rcParams.update(\n",
     "    {\n",

doc/tutorials/uniform_sampling_of_orientation_space.ipynb

@@ -80,7 +80,6 @@
     "from orix.sampling import get_sample_fundamental\n",
     "from orix.vector import Vector3d\n",
     "\n",
-    "\n",
     "plt.rcParams.update(\n",
     "    {\n",
     "        \"axes.grid\": True,\n",

examples/stereographic_projection/plot_symmetry_advanced.py

@@ -0,0 +1,66 @@
+#
+# Copyright 2018-2026 the orix developers
+#
+# This file is part of orix.
+#
+# orix is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# orix is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with orix. If not, see <http://www.gnu.org/licenses/>.
+#
+
+r"""
+===============================
+Altering Crystal Symmetry Plots
+===============================
+
+This example demonstrates some advanced methods for altering
+stereographic plots of symmetries. For a more general example, see
+:ref:`sphx_glr_plot_symmetry_operations.py`. For examples of how to make
+symmetry objects, see :ref:`create_symmetry.py`
+"""
+
+import matplotlib.pyplot as plt
+import numpy as np
+
+import orix.plot as opl
+import orix.quaternion as oqu
+import orix.vector as ove
+
+# Set a random seed for reproducability
+np.random.seed = 897897
+# Register our custom Matplotlib projections
+opl.register_projections()
+# Use the PointGroup Class to create a Symmetry from a common shorthand name
+pg_Oh = oqu.symmetry.PointGroups.get("m-3m")
+
+########################################################################################
+# Typically, plots can be made using the built-in plot function. By default this
+# will create a matplotlib Figure and Axis object, plot a single asymmetric
+# vector, and add the Point Group name as the title
+pg_Oh.plot()
+
+########################################################################################
+# Alternatively though, by creating a figure beforehand and passing the Axis
+# in, it's possible to modify this plot as desired, for example by adding
+# additional plots, changing the title, or modifying elements.
+
+v = ove.Vector3d.random(10)
+v_symm = pg_Oh.outer(v).flatten()
+fig, ax = plt.subplots(1, 1, subplot_kw={"projection": "stereographic"})
+pg_Oh.plot(ax=ax, show_name=False)
+ax.set_title("my cool custom title")
+ax.scatter(v_symm)
+
+for i in range(len(ax.lines)):
+    ax.lines[i].set_c([0, 1, 1])
+
+plt.show()

examples/stereographic_projection/plot_symmetry_operations.py

@@ -21,53 +21,55 @@
 Plot symmetry operations
 ========================
 
-This example shows how to draw proper symmetry operations :math:`s`
-(no reflections or inversions).
+This example shows how stereographic projections with symmetry operation
+markers can be automatically generated for the 32 crystallographic point
+groups.
+
+The ordering used here follows the one given in section 9.2 of "Structures
+of Materials" (DeGraef et.al, 2nd edition, 2012). This ordering starts with
+the 5 cyclic groups (C1, C2, C3, C4, and C6), followed by the 4 dihedral
+groups (D2, D3, D4, and D6). Next are the same groups combined with inversion
+centers (Ci, Cs, C3i, S4, and C3h), perpendicular mirror planes (C2h, C4h,
+and C6h), vertical mirror planes (C2v, C3v, C4v, and C6v), and diagonal
+mirror planes (D3d, D2d, and D3h). Next are groups formed from permutations
+of cyclic and dihedral groups (D2h, D4h, and D6h), and finally the groups
+with 3-fold rotations around the 111 axes (T, O, Th, Td, and Oh).
+
+The plots themselves as well as their labels follow the standards given
+in Table 10.2.2 of the "International Tables for Crystallography, Volume
+A" (ITC). Both the nomenclature and marker styles thus differ slightly from
+many textbooks, including "Structure of Materials", as there are arbitrary
+convention choices in ITC regarding both Schoenflies notation and marker
+style.
+
+Orix uses Schoenflies Notation (left label above each plot) for the default
+symmetry group names since they are short and always begin with a letter,
+but both Schoenflies and Hermann-Mauguin (right label above each plot) names
+can be used to look up symmetry groups using `PointGroups.get()`
 """
 
 import matplotlib.pyplot as plt
 
-from orix.plot import register_projections
-from orix.vector import Vector3d
+import orix.plot as opl
+import orix.quaternion as oqu
+import orix.vector as ove
 
-register_projections()  # Register our custom Matplotlib projections
+opl.register_projections()  # Register our custom Matplotlib projections
 
-marker_size = 200
-fig, (ax0, ax1) = plt.subplots(
-    ncols=2,
-    subplot_kw={"projection": "stereographic"},
-    layout="tight",
-)
+# create a list of the 32 crystallographic point groups
+point_groups = oqu.symmetry.PointGroups.get_set("procedural")
+
+# show the table of symmetry information
+print(point_groups)
 
-ax0.set_title("432", pad=20)
-# 4-fold (outer markers will be clipped a bit...)
-v4fold = Vector3d([[0, 0, 1], [1, 0, 0], [-1, 0, 0], [0, 1, 0], [0, -1, 0]])
-ax0.symmetry_marker(v4fold, fold=4, c="C4", s=marker_size)
-ax0.draw_circle(v4fold, color="C4")
-# 3-fold
-v3fold = Vector3d([[1, 1, 1], [1, -1, 1], [-1, -1, 1], [-1, 1, 1]])
-ax0.symmetry_marker(v3fold, fold=3, c="C3", s=marker_size)
-ax0.draw_circle(v3fold, color="C3")
-# 2-fold
-# fmt: off
-v2fold = Vector3d(
-    [
-        [ 1,  0, 1],
-        [ 0,  1, 1],
-        [-1,  0, 1],
-        [ 0, -1, 1],
-        [ 1,  1, 0],
-        [-1, -1, 0],
-        [-1,  1, 0],
-        [ 1, -1, 0],
-    ]
+# prepare the plots
+fig, ax = plt.subplots(
+    4, 8, subplot_kw={"projection": "stereographic"}, figsize=[14, 10]
 )
-# fmt: on
-ax0.symmetry_marker(v2fold, fold=2, c="C2", s=marker_size)
-ax0.draw_circle(v2fold, color="C2")
+ax = ax.flatten()
 
-ax1.set_title("222", pad=20)
-# 2-fold
-v2fold = Vector3d([[0, 0, 1], [1, 0, 0], [-1, 0, 0], [0, 1, 0], [0, -1, 0]])
-ax1.symmetry_marker(v2fold, fold=2, c="C2", s=2 * marker_size)
-ax1.draw_circle(v2fold, color="C2")
+# create a vector to mirror over axes
+v = ove.Vector3d.from_polar(65, 80, degrees=True)
+# Iterate through the 32 Point groups
+for i, pg in enumerate(point_groups):
+    pg.plot(asymmetric_vector=v, ax=ax[i])

orix/crystal_map/_phase.py

@@ -33,13 +33,7 @@
 import numpy as np
 
 from orix.plot._util.color import get_matplotlib_color
-from orix.quaternion.symmetry import (
-    _EDAX_POINT_GROUP_ALIASES,
-    VALID_SYSTEMS,
-    Symmetry,
-    _groups,
-    get_point_group,
-)
+from orix.quaternion.symmetry import VALID_SYSTEMS, PointGroups, Symmetry
 from orix.vector.miller import Miller
 from orix.vector.vector3d import Vector3d
 
@@ -225,7 +219,7 @@ def point_group(self) -> Symmetry | None:
             Point group.
         """
         if self.space_group is not None:
-            return get_point_group(self.space_group.number)
+            return PointGroups.from_space_group(self.space_group.number)
         else:
             return self._point_group
 
@@ -235,14 +229,7 @@ def point_group(self, value: int | str | Symmetry | None) -> None:
         if isinstance(value, int):
             value = str(value)
         if isinstance(value, str):
-            for key, aliases in _EDAX_POINT_GROUP_ALIASES.items():
-                if value in aliases:
-                    value = key
-                    break
-            for point_group in _groups:
-                if value == point_group.name:
-                    value = point_group
-                    break
+            value = PointGroups.get(value)
         if not isinstance(value, Symmetry) and value is not None:
             raise ValueError(
                 f"{value!r} must be of type {Symmetry}, the name of a valid point group"
@@ -486,7 +473,13 @@ def new_structure_matrix_from_alignment(
 
 
 def default_lattice(system: VALID_SYSTEMS) -> Lattice:
-    if system in ["triclinic", "monoclinic", "orthorhombic", "tetragonal", "cubic"]:
+    if system in [
+        "triclinic",
+        "monoclinic",
+        "orthorhombic",
+        "tetragonal",
+        "cubic",
+    ]:
         lat = Lattice()
     elif system in ["trigonal", "hexagonal"]:
         lat = Lattice(1, 1, 1, 90, 90, 120)