torch install options

ramannoodle/io/generic.py

@@ -18,7 +18,11 @@
 
 from ramannoodle.structure.reference import ReferenceStructure
 import ramannoodle.io.vasp as vasp_io
-from ramannoodle.polarizability.torch.dataset import PolarizabilityDataset
+
+try:
+    from ramannoodle.polarizability.torch import dataset
+except ModuleNotFoundError:
+    import ramannoodle.polarizability.torch.dummy_dataset as dataset  # type: ignore
 
 # These  map between file formats and appropriate IO functions.
 _PHONON_READERS = {
@@ -189,7 +193,7 @@ def read_structure_and_polarizability(
 def read_polarizability_dataset(
     filepaths: str | Path | list[str] | list[Path],
     file_format: str,
-) -> PolarizabilityDataset:
+) -> dataset.PolarizabilityDataset:
     """Read polarizability dataset from files.
 
     Parameters

ramannoodle/io/io_utils.py

@@ -15,7 +15,11 @@
     IncompatibleStructureException,
 )
 from ramannoodle.globals import ATOM_SYMBOLS
-from ramannoodle.polarizability.torch.dataset import PolarizabilityDataset
+
+try:
+    from ramannoodle.polarizability.torch import dataset
+except ModuleNotFoundError:
+    import ramannoodle.polarizability.torch.dummy_dataset as dataset  # type: ignore
 
 
 def _skip_file_until_line_contains(file: TextIO, content: str) -> str:
@@ -95,7 +99,7 @@ def _read_polarizability_dataset(
         [str | Path],
         tuple[NDArray[np.float64], list[int], NDArray[np.float64], NDArray[np.float64]],
     ],
-) -> PolarizabilityDataset:
+) -> dataset.PolarizabilityDataset:
     """Read polarizability dataset from OUTCAR files.
 
     Parameters
@@ -114,7 +118,11 @@ def _read_polarizability_dataset(
         File has an unexpected format.
     IncompatibleFileException
         File is incompatible with the dataset.
+    ModuleNotFoundError
+        Torch installation could not be found.
     """
+    if not dataset.TORCH_PRESENT:
+        raise ModuleNotFoundError("torch installation not found")
     filepaths = pathify_as_list(filepaths)
 
     lattices: list[NDArray[np.float64]] = []
@@ -143,7 +151,7 @@ def _read_polarizability_dataset(
         positions_list.append(positions)
         polarizabilities.append(polarizability)
 
-    return PolarizabilityDataset(
+    return dataset.PolarizabilityDataset(
         np.array(lattices),
         atomic_numbers_list,
         np.array(positions_list),

ramannoodle/io/vasp/outcar.py

@@ -16,7 +16,11 @@
 from ramannoodle.dynamics.phonon import Phonons
 from ramannoodle.dynamics.trajectory import Trajectory
 from ramannoodle.structure.reference import ReferenceStructure
-from ramannoodle.polarizability.torch.dataset import PolarizabilityDataset
+
+try:
+    from ramannoodle.polarizability.torch import dataset
+except ModuleNotFoundError:
+    import ramannoodle.polarizability.torch.dummy_dataset as dataset  # type: ignore
 
 
 # Utilities for OUTCAR. Warning: some of these functions partially read files.
@@ -400,7 +404,7 @@ def read_structure_and_polarizability(
 
 def read_polarizability_dataset(
     filepaths: str | Path | list[str] | list[Path],
-) -> PolarizabilityDataset:
+) -> dataset.PolarizabilityDataset:
     """Read polarizability dataset from OUTCAR files.
 
     Parameters

ramannoodle/io/vasp/vasprun.py

@@ -14,7 +14,11 @@
 from ramannoodle.dynamics.phonon import Phonons
 from ramannoodle.dynamics.trajectory import Trajectory
 from ramannoodle.structure.reference import ReferenceStructure
-from ramannoodle.polarizability.torch.dataset import PolarizabilityDataset
+
+try:
+    from ramannoodle.polarizability.torch import dataset
+except ModuleNotFoundError:
+    import ramannoodle.polarizability.torch.dummy_dataset as dataset  # type: ignore
 
 
 def _get_root_element(file: TextIO) -> Element:
@@ -195,7 +199,7 @@ def read_structure_and_polarizability(
 
 def read_polarizability_dataset(
     filepaths: str | Path | list[str] | list[Path],
-) -> PolarizabilityDataset:
+) -> dataset.PolarizabilityDataset:
     """Read polarizability dataset from OUTCAR files.
 
     Parameters

ramannoodle/polarizability/torch/dataset.py

@@ -12,6 +12,8 @@
 from ramannoodle.exceptions import verify_ndarray_shape, verify_list_len, get_type_error
 import ramannoodle.polarizability.torch.utils as rn_torch_utils
 
+TORCH_PRESENT = True
+
 
 def _scale_and_flatten_polarizabilities(
     polarizabilities: Tensor,

ramannoodle/polarizability/torch/dummy_dataset.py

@@ -0,0 +1,44 @@
+"""Dummy polarizability PyTorch dataset.
+
+Used when torch installation cannot be found.
+
+:meta private:
+"""
+
+import numpy as np
+from numpy.typing import NDArray
+
+TORCH_PRESENT = False
+
+
+class PolarizabilityDataset:  # pylint: disable=too-few-public-methods
+    """PyTorch dataset of atomic structures and polarizabilities.
+
+    Polarizabilities are scaled and flattened into vectors containing the six
+    independent tensor components.
+
+    Parameters
+    ----------
+    lattices
+        | (Å) 3D array with shape (S,3,3) where S is the number of samples.
+    atomic_numbers
+        | List of length S containing lists of length N, where N is the number of atoms.
+    positions
+        | (fractional) 3D array with shape (S,N,3).
+    polarizabilities
+        | 3D array with shape (S,3,3).
+    scale_mode
+        | Supports ``"standard"`` (standard scaling), ``"stddev"`` (division by
+        | standard deviation), and ``"none"`` (no scaling).
+
+    """
+
+    def __init__(  # pylint: disable=too-many-arguments
+        self,
+        lattices: NDArray[np.float64],
+        atomic_numbers: list[list[int]],
+        positions: NDArray[np.float64],
+        polarizabilities: NDArray[np.float64],
+        scale_mode: str = "standard",
+    ):
+        raise ModuleNotFoundError("torch installation not found")