Implement web JSON export

euphonic/cli/dispersion.py

@@ -5,17 +5,21 @@
 
 from euphonic.plot import plot_1d
 from euphonic.styles import base_style
+from euphonic.writers.phonon_website import write_phonon_website_json
 from euphonic import Spectrum1D, ForceConstants, QpointFrequencies
 from .utils import (load_data_from_file, get_args, _bands_from_force_constants,
                     _compose_style,
                     _get_q_distance, matplotlib_save_or_show, _get_cli_parser,
+                    _get_title,
                     _calc_modes_kwargs, _plot_label_kwargs)
 
 
 def main(params: Optional[List[str]] = None) -> None:
     args = get_args(get_parser(), params)
 
-    frequencies_only = not args.reorder  # Need eigenvectors to reorder
+    # Need eigenvectors to reorder bands or write website JSON
+    frequencies_only = args.save_web_json is None and not args.reorder
+
     data = load_data_from_file(args.filename, verbose=True,
                                frequencies_only=frequencies_only)
     if not frequencies_only and type(data) is QpointFrequencies:
@@ -33,6 +37,12 @@ def main(params: Optional[List[str]] = None) -> None:
         split_args = {'btol': args.btol}
         x_tick_labels = None
 
+    if args.save_web_json is not None:
+        write_phonon_website_json(modes=bands,
+                                  name=_get_title(args.filename, args.title),
+                                  output_file=args.save_web_json,
+                                  x_tick_labels=x_tick_labels)
+
     bands.frequencies_unit = args.energy_unit
 
     print("Mapping modes to 1D band-structure")
@@ -54,6 +64,7 @@ def main(params: Optional[List[str]] = None) -> None:
 
     if args.save_json:
         spectrum.to_json_file(args.save_json)
+
     with matplotlib.style.context(style):
         _ = plot_1d(spectra,
                     ymin=args.e_min,
@@ -63,7 +74,7 @@ def main(params: Optional[List[str]] = None) -> None:
 
 
 def get_parser() -> ArgumentParser:
-    parser, _ = _get_cli_parser(features={'read-fc', 'read-modes', 'plotting',
+    parser, groups = _get_cli_parser(features={'read-fc', 'read-modes', 'plotting',
                                           'q-e', 'btol'})
     parser.description = (
         'Plots a band structure from the file provided. If a force '
@@ -77,4 +88,11 @@ def get_parser() -> ArgumentParser:
         action='store_true',
         help=('Try to determine branch crossings from eigenvectors and'
               ' rearrange frequencies accordingly'))
+    groups["plotting"].add_argument(
+        '--save-web-json',
+        dest='save_web_json',
+        default=None,
+        help='Write JSON file for use with phonon website',
+    )
+
     return parser

euphonic/cli/utils.py

@@ -15,7 +15,6 @@
                       QpointPhononModes, Spectrum1D, Spectrum1DCollection,
                       Quantity, ureg)
 import euphonic.util
-Unit = ureg.Unit
 
 
 def _load_euphonic_json(filename: Union[str, os.PathLike],
@@ -671,7 +670,7 @@ def __call__(self, parser, args, values, option_string=None):
         section.add_argument(
             '-s', '--save-to', dest='save_to', default=None,
             help='Save resulting plot to a file with this name')
-        section.add_argument('--title', type=str, default='',
+        section.add_argument('--title', type=str, default=None,
                              help='Plot title')
         section.add_argument('--x-label', '--xlabel', type=str, default=None,
                              dest='xlabel', help='Plot x-axis label')
@@ -934,3 +933,8 @@ def _compose_style(
 
     style.append(explicit_args)
     return style
+
+
+def _get_title(filename: str, title: str | None = None) -> str:
+    """Get a plot title: either user-provided string, or from filename"""
+    return title if title is not None else pathlib.Path(filename).stem

euphonic/plot.py

@@ -99,7 +99,7 @@ def plot_1d(spectra: Union[Spectrum1D,
                            Spectrum1DCollection,
                            Sequence[Spectrum1D],
                            Sequence[Spectrum1DCollection]],
-            title: str = '',
+            title: str | None = None,
             xlabel: str = '',
             ylabel: str = '',
             ymin: Optional[float] = None,
@@ -191,7 +191,7 @@ def plot_1d(spectra: Union[Spectrum1D,
     ax.set_xlabel(xlabel)
     ax.set_ylabel(ylabel)
 
-    fig.suptitle(title)
+    fig.suptitle('' if title is None else title)
     return fig
 
 
@@ -249,7 +249,7 @@ def plot_2d(spectra: Union[Spectrum2D, Sequence[Spectrum2D]],
             vmin: Optional[float] = None,
             vmax: Optional[float] = None,
             cmap: Optional[Union[str, Colormap]] = None,
-            title: str = '',
+            title: str | None = None,
             xlabel: str = '',
             ylabel: str = '') -> Figure:
     """
@@ -319,7 +319,7 @@ def _get_minmax_intensity(spectrum: Spectrum2D) -> Tuple[float, float]:
     ax.set_xlabel(xlabel)
     ax.set_ylabel(ylabel)
 
-    fig.suptitle(title)
+    fig.suptitle('' if title is None else title)
 
     return fig
 

euphonic/qpoint_phonon_modes.py

@@ -1,5 +1,7 @@
+"""Data container (with methods) for phonon frequencies and eigenvectors"""
+
 import math
-from typing import Dict, Optional, Union, TypeVar, Any, Type
+from typing import Any, Dict, Optional, Union, Type, TypeVar
 from collections.abc import Mapping
 
 import numpy as np

euphonic/spectra.py

@@ -31,6 +31,7 @@
 
 
 CallableQuantity = Callable[[Quantity], Quantity]
+XTickLabels = list[tuple[int, str]]
 
 
 class Spectrum(ABC):
@@ -84,11 +85,12 @@ def copy(self: T) -> T:
         ...
 
     @property
-    def x_tick_labels(self) -> List[Tuple[int, str]]:
+    def x_tick_labels(self) -> XTickLabels:
+        """x-axis tick labels (e.g. high-symmetry point locations)"""
         return self._x_tick_labels
 
     @x_tick_labels.setter
-    def x_tick_labels(self, value: Sequence[Tuple[int, str]]) -> None:
+    def x_tick_labels(self, value: XTickLabels) -> None:
         err_msg = ('x_tick_labels should be of type '
                    'Sequence[Tuple[int, str]] e.g. '
                    '[(0, "label1"), (5, "label2")]')
@@ -171,10 +173,9 @@ def _ranges_from_indices(indices: Union[Sequence[int], np.ndarray]
         return ranges
 
     @staticmethod
-    def _cut_x_ticks(x_tick_labels: Union[Sequence[Tuple[int, str]], None],
+    def _cut_x_ticks(x_tick_labels: XTickLabels | None,
                      x0: int,
-                     x1: Union[int, None]) -> Union[List[Tuple[int, str]],
-                                                    None]:
+                     x1: int | None) -> XTickLabels | None:
         """Crop and shift x labels to new x range"""
         if x_tick_labels is None:
             return None
@@ -419,7 +420,7 @@ class Spectrum1D(Spectrum):
     T = TypeVar('T', bound='Spectrum1D')
 
     def __init__(self, x_data: Quantity, y_data: Quantity,
-                 x_tick_labels: Optional[Sequence[Tuple[int, str]]] = None,
+                 x_tick_labels: Optional[XTickLabels] = None,
                  metadata: Optional[Dict[str, Union[int, str]]] = None
                  ) -> None:
         """
@@ -1147,7 +1148,7 @@ class Spectrum1DCollection(SpectrumCollectionMixin,
 
     def __init__(
             self, x_data: Quantity, y_data: Quantity,
-            x_tick_labels: Optional[Sequence[Tuple[int, str]]] = None,
+            x_tick_labels: Optional[XTickLabels] = None,
             metadata: Optional[Dict[str, Union[str, int, LineData]]] = None
     ) -> None:
         """
@@ -1451,7 +1452,7 @@ class Spectrum2D(Spectrum):
 
     def __init__(self, x_data: Quantity, y_data: Quantity,
                  z_data: Quantity,
-                 x_tick_labels: Optional[Sequence[Tuple[int, str]]] = None,
+                 x_tick_labels: Optional[XTickLabels] = None,
                  metadata: Optional[Metadata] = None
                  ) -> None:
         """
@@ -1875,7 +1876,7 @@ class Spectrum2DCollection(SpectrumCollectionMixin,
 
     def __init__(
             self, x_data: Quantity, y_data: Quantity, z_data: Quantity,
-            x_tick_labels: Optional[Sequence[Tuple[int, str]]] = None,
+            x_tick_labels: Optional[XTickLabels] = None,
             metadata: Optional[Metadata] = None
     ) -> None:
         _check_constructor_inputs(