Add precision and fix pickling

depthcharge/data/spectrum_datasets.py

@@ -8,7 +8,7 @@
 from os import PathLike
 from pathlib import Path
 from tempfile import TemporaryDirectory
-from typing import Any
+from typing import Any, Literal
 
 import lance
 import polars as pl
@@ -28,6 +28,10 @@
 class CollateFnMixin:
     """Define a common collate function."""
 
+    def __init__(self) -> None:
+        """Specify the float precision."""
+        self.precision = torch.float64
+
     def collate_fn(
         self,
         batch: Iterable[dict[Any]],
@@ -62,10 +66,22 @@ def collate_fn(
         batch = torch.utils.data.default_collate(batch)
         batch["mz_array"] = mz_array
         batch["intensity_array"] = intensity_array
+
+        for key, val in batch.items():
+            if isinstance(val, torch.Tensor) and torch.is_floating_point(val):
+                batch[key] = val.type(self.precision)
+
         return batch
 
-    def loader(self, **kwargs: dict) -> DataLoader:
+    def loader(
+        self,
+        precision: Literal[
+            torch.float16, torch.float32, torch.float64
+        ] = torch.float64,
+        **kwargs: dict,
+    ) -> DataLoader:
         """Create a suitable PyTorch DataLoader."""
+        self.precision = precision
         if kwargs.get("collate_fn", False):
             warnings.warn("The default collate_fn was overridden.")
         else:

depthcharge/tokenizers/peptides.py

@@ -94,6 +94,21 @@ def __init__(
 
         super().__init__(list(self.residues.keys()))
 
+    def __getstate__(self) -> dict:
+        """How to pickle the object."""
+        self.residues = dict(self.residues)
+        return self.__dict__
+
+    def __setstate__(self, state: dict) -> None:
+        """How to unpickle the object."""
+        self.__dict__ = state
+        residues = self.residues
+        self.residues = nb.typed.Dict.empty(
+            nb.types.unicode_type,
+            nb.types.float64,
+        )
+        self.residues.update(residues)
+
     def split(self, sequence: str) -> list[str]:
         """Split a ProForma peptide sequence.
 

tests/unit_tests/test_data/test_datasets.py

@@ -1,4 +1,5 @@
 """Test the datasets."""
+import pickle
 import shutil
 
 import pytest
@@ -154,3 +155,33 @@ def test_peptide_dataset(tokenizer):
 
     torch.testing.assert_close(dset.tokens, tokenizer.tokenize(seqs))
     torch.testing.assert_close(dset.charges, charges)
+
+
+def test_pickle(tokenizer, tmp_path, mgf_small):
+    """Test that datasets can be pickled."""
+    dataset = SpectrumDataset(mgf_small, path=tmp_path / "test")
+    pkl_file = tmp_path / "test.pkl"
+    with pkl_file.open("wb+") as pkl:
+        pickle.dump(dataset, pkl)
+
+    with pkl_file.open("rb") as pkl:
+        loaded = pickle.load(pkl)
+
+    assert len(dataset) == len(loaded)
+
+    dataset = AnnotatedSpectrumDataset(
+        [mgf_small],
+        tokenizer,
+        "seq",
+        tmp_path / "test.lance",
+        custom_fields={"seq": ["params", "seq"]},
+    )
+    pkl_file = tmp_path / "test.pkl"
+
+    with pkl_file.open("wb+") as pkl:
+        pickle.dump(dataset, pkl)
+
+    with pkl_file.open("rb") as pkl:
+        loaded = pickle.load(pkl)
+
+    assert len(dataset) == len(loaded)