Add Type Hints to MDAnalysis.analysis.rms

mypy.ini

@@ -3,6 +3,9 @@ ignore_missing_imports = True
 exclude = doc/sphinx/source/
 
 
+[mypy-MDAnalysis.analysis.rms]
+ignore_errors = False
+
 [mypy-MDAnalysis.analysis.*]
 ignore_errors = True
 

package/AUTHORS

@@ -265,12 +265,8 @@ Chronological list of authors
   - Raúl Lois-Cuns  
   - Pranay Pelapkar
   - Shreejan Dolai
-  - Tanisha Dubey
-  - Brady Johnston
-2026
-  - Mohammad Ayaan
-  - Khushi Phougat
-
+  - Chetan Agarwal
+
 External code
 -------------
 

package/MDAnalysis/analysis/rms.py

@@ -166,16 +166,38 @@
 import logging
 import warnings
 
-from ..lib import qcprot as qcp
+from ..lib import qcprot as qcp  # type: ignore[attr-defined]
 from ..analysis.base import AnalysisBase, ResultsGroup
 from ..exceptions import SelectionError
 from ..lib.util import asiterable, iterable, get_weights
 
+from typing import (
+    Optional,
+    Union,
+    List,
+    Dict,
+    Any,
+    Sequence,
+    Tuple,
+    TYPE_CHECKING,
+)
+from numpy.typing import NDArray
+
+if TYPE_CHECKING:  # pragma: no cover
+    from ..core.groups import AtomGroup
+    from ..core.universe import Universe
+
 
 logger = logging.getLogger("MDAnalysis.analysis.rmsd")
 
 
-def rmsd(a, b, weights=None, center=False, superposition=False):
+def rmsd(
+    a: NDArray,
+    b: NDArray,
+    weights: Optional[NDArray] = None,
+    center: bool = False,
+    superposition: bool = False,
+) -> float:
     r"""Returns RMSD between two coordinate sets `a` and `b`.
 
     `a` and `b` are arrays of the coordinates of N atoms of shape
@@ -282,7 +304,9 @@ def rmsd(a, b, weights=None, center=False, superposition=False):
             return np.sqrt(np.sum((a - b) ** 2) / N)
 
 
-def process_selection(select):
+def process_selection(
+    select: Union[str, Tuple[str, str], Dict[str, str]]
+) -> Dict[str, Any]:
     """Return a canonical selection dictionary.
 
     Parameters
@@ -365,6 +389,14 @@ class RMSD(AnalysisBase):
 
     _analysis_algorithm_is_parallelizable = True
 
+    atomgroup: Union["AtomGroup", "Universe"]
+    reference: Union["AtomGroup", "Universe"]
+    groupselections: List[Dict[str, Any]]
+    weights: Optional[Union[str, NDArray, List[Any]]]
+    weights_groupselections: Union[bool, List[Any]]
+    tol_mass: float
+    ref_frame: int
+
     @classmethod
     def get_supported_backends(cls):
         return (
@@ -375,15 +407,17 @@ def get_supported_backends(cls):
 
     def __init__(
         self,
-        atomgroup,
-        reference=None,
-        select="all",
-        groupselections=None,
-        weights=None,
-        weights_groupselections=False,
-        tol_mass=0.1,
-        ref_frame=0,
-        **kwargs,
+        atomgroup: Union["AtomGroup", "Universe"],
+        reference: Optional[Union["AtomGroup", "Universe"]] = None,
+        select: Union[str, Dict[str, str], Tuple[str, str]] = "all",
+        groupselections: Optional[
+            Sequence[Union[str, Dict[str, str], Tuple[str, str]]]
+        ] = None,
+        weights: Optional[Union[str, NDArray, List[Any]]] = None,
+        weights_groupselections: Union[bool, List[Any]] = False,
+        tol_mass: float = 0.1,
+        ref_frame: int = 0,
+        **kwargs: Any,
     ):
         r"""Parameters
         ----------
@@ -631,7 +665,7 @@ def __init__(
 
         if iterable(self.weights):
             element_lens = []
-            for element in self.weights:
+            for element in self.weights:  # type: ignore[union-attr]
                 if iterable(element):
                     element_lens.append(len(element))
                 else:
@@ -646,13 +680,13 @@ def __init__(
             get_weights(self.mobile_atoms, self.weights)
 
         if self.weights_groupselections:
-            if len(self.weights_groupselections) != len(self.groupselections):
+            if len(self.weights_groupselections) != len(self.groupselections):  # type: ignore[arg-type]
                 raise ValueError(
                     "Length of weights_groupselections is not equal to "
                     "length of groupselections "
                 )
             for weights, atoms, selection in zip(
-                self.weights_groupselections,
+                self.weights_groupselections,  # type: ignore[arg-type]
                 self._groupselections_atoms,
                 self.groupselections,
             ):
@@ -665,7 +699,7 @@ def __init__(
                         + " happens in selection %s" % selection["mobile"]
                     )
 
-    def _prepare(self):
+    def _prepare(self) -> None:
         self._n_atoms = self.mobile_atoms.n_atoms
         if not self.weights_groupselections:
             if not iterable(
@@ -679,15 +713,17 @@ def _prepare(self):
                     self.groupselections
                 )
 
+        weights_gs = self.weights_groupselections
+        assert isinstance(weights_gs, list)  # pragma: no cover
         for igroup, (weights, atoms) in enumerate(
-            zip(self.weights_groupselections, self._groupselections_atoms)
+            zip(weights_gs, self._groupselections_atoms)
         ):
             if str(weights) == "mass":
-                self.weights_groupselections[igroup] = atoms["mobile"].masses
+                weights_gs[igroup] = atoms["mobile"].masses
             if weights is not None:
-                self.weights_groupselections[igroup] = np.asarray(
-                    self.weights_groupselections[igroup], dtype=np.float64
-                ) / np.mean(self.weights_groupselections[igroup])
+                weights_gs[igroup] = np.asarray(
+                    weights_gs[igroup], dtype=np.float64
+                ) / np.mean(weights_gs[igroup])
         # add the array of weights to weights_select
         self.weights_select = get_weights(self.mobile_atoms, self.weights)
         self.weights_ref = get_weights(self.ref_atoms, self.weights)
@@ -722,7 +758,7 @@ def _prepare(self):
             # Move back to the original frame
             self.reference.universe.trajectory[current_frame]
 
-        self._ref_coordinates64 = self._ref_coordinates.astype(np.float64)
+        self._ref_coordinates64 = self._ref_coordinates.astype(np.float64)  # type: ignore[assignment]
 
         if self._groupselections_atoms:
             # Only carry out a rotation if we want to calculate secondary
@@ -733,7 +769,7 @@ def _prepare(self):
             self._rot = np.zeros(9, dtype=np.float64)  # allocate space
             self._R = self._rot.reshape(3, 3)
         else:
-            self._rot = None
+            self._rot = None  # type: ignore[assignment]
 
         self.results.rmsd = np.zeros(
             (self.n_frames, 3 + len(self._groupselections_atoms))
@@ -746,7 +782,7 @@ def _prepare(self):
     def _get_aggregator(self):
         return ResultsGroup(lookup={"rmsd": ResultsGroup.ndarray_vstack})
 
-    def _single_frame(self):
+    def _single_frame(self) -> None:
         mobile_com = self.mobile_atoms.center(self.weights_select).astype(
             np.float64
         )
@@ -787,6 +823,9 @@ def _single_frame(self):
 
             # 2) calculate secondary RMSDs (without any further
             #    superposition)
+            assert isinstance(
+                self.weights_groupselections, list
+            )  # pragma: no cover
             for igroup, (refpos, atoms) in enumerate(
                 zip(
                     self._groupselections_ref_coords64,
@@ -846,7 +885,7 @@ class RMSF(AnalysisBase):
     def get_supported_backends(cls):
         return ("serial",)
 
-    def __init__(self, atomgroup, **kwargs):
+    def __init__(self, atomgroup: "AtomGroup", **kwargs: Any):
         r"""Parameters
         ----------
         atomgroup : AtomGroup
@@ -969,18 +1008,18 @@ def __init__(self, atomgroup, **kwargs):
         super(RMSF, self).__init__(atomgroup.universe.trajectory, **kwargs)
         self.atomgroup = atomgroup
 
-    def _prepare(self):
+    def _prepare(self) -> None:
         self.sumsquares = np.zeros((self.atomgroup.n_atoms, 3))
         self.mean = self.sumsquares.copy()
 
-    def _single_frame(self):
+    def _single_frame(self) -> None:
         k = self._frame_index
         self.sumsquares += (k / (k + 1.0)) * (
             self.atomgroup.positions - self.mean
         ) ** 2
         self.mean = (k * self.mean + self.atomgroup.positions) / (k + 1)
 
-    def _conclude(self):
+    def _conclude(self) -> None:
         k = self._frame_index
         self.results.rmsf = np.sqrt(self.sumsquares.sum(axis=1) / (k + 1))
 

testsuite/MDAnalysisTests/analysis/test_rms.py

@@ -391,6 +391,26 @@ def test_rmsd_list_of_weights_wrong_length(self, universe):
                 weights_groupselections=[None],
             )
 
+    def test_rmsd_groupselections_with_mass_weights(
+        self, universe, client_RMSD
+    ):
+        # Test to ensure line 694 coverage with weights="mass" in groupselections
+        # This tests the code path where weights="mass" is propagated to
+        # groupselections when weights_groupselections=False
+        RMSD = MDAnalysis.analysis.rms.RMSD(
+            universe,
+            select="backbone",
+            groupselections=["name CA", "backbone and resid 1:10"],
+            weights="mass",
+            weights_groupselections=False,
+        ).run(step=49, **client_RMSD)
+
+        # Just verify it runs without error and produces valid results
+        assert RMSD.results.rmsd.shape[0] == 2  # 2 frames (0 and 49)
+        assert (
+            RMSD.results.rmsd.shape[1] == 5
+        )  # frame, time, rmsd, group1, group2
+
     def test_rmsd_group_selections(
         self, universe, correct_values_group, client_RMSD
     ):