Avoid ndarray copy

phono3py/api_phono3py.py

@@ -822,7 +822,7 @@ def _set_band_indices(self, band_indices=None):
             self._band_indices = [np.arange(num_band, dtype="int64")]
         else:
             self._band_indices = [np.array(bi, dtype="int64") for bi in band_indices]
-        self._band_indices_flatten = np.hstack(self._band_indices).astype("int64")
+        self._band_indices_flatten = np.hstack(self._band_indices, dtype="int64")
 
     @property
     def masses(self) -> NDArray:

phono3py/cui/phono3py_script.py

@@ -929,7 +929,7 @@ def _run_isotope_then_exit(
     """Run isotope scattering calculation."""
     mass_variances = settings.mass_variances
     if settings.band_indices is not None:
-        band_indices = np.hstack(settings.band_indices).astype("int64")
+        band_indices = np.hstack(settings.band_indices, dtype="int64")
     else:
         band_indices = None
     iso = Phono3pyIsotope(

phono3py/file_IO.py

@@ -335,7 +335,7 @@ def write_fc3_to_hdf5(
         Filename to be used.
     p2s_map : ndarray, optional
         Primitive atom indices in supercell index system shape=(n_patom,),
-        dtype=intc
+        dtype=int64
     fc3_cutoff : float, optional
         Cutoff distance for fc3.
     compression : str or int, optional
@@ -770,7 +770,7 @@ def write_spectral_function_to_hdf5(
     if all_band_exist:
         _band_indices = None
     else:
-        _band_indices = np.hstack(band_indices).astype("int64")
+        _band_indices = np.hstack(band_indices, dtype="int64")
     suffix = _get_filename_suffix(
         mesh, grid_point=grid_point, band_indices=_band_indices, sigma=sigma
     )

phono3py/phonon/solver.py

@@ -270,4 +270,4 @@ def _get_fc_elements_mapping(dm: DynamicalMatrix, fc: NDArray[np.double]):
         fc_p2s = np.arange(len(p2s_map), dtype="int64")
         fc_s2p = s2pp_map
 
-    return np.array(fc_p2s, dtype="int64"), np.array(fc_s2p, dtype="int64")
+    return fc_p2s, fc_s2p

phono3py/phonon3/fc3.py

@@ -280,10 +280,10 @@ def set_permutation_symmetry_compact_fc3(fc3, primitive):
         s2pp_map, nsym_list = get_nsym_list_and_s2pp(s2p_map, p2p_map, permutations)
         phono3c.permutation_symmetry_compact_fc3(
             fc3,
-            np.array(permutations, dtype="int64", order="C"),
-            np.array(s2pp_map, dtype="int64"),
-            np.array(p2s_map, dtype="int64"),
-            np.array(nsym_list, dtype="int64"),
+            permutations,
+            s2pp_map,
+            p2s_map,
+            nsym_list,
         )
     except ImportError as exc:
         text = (
@@ -333,11 +333,6 @@ def set_translational_invariance_compact_fc3(fc3, primitive: Primitive):
         p2p_map = primitive.p2p_map
         permutations = primitive.atomic_permutations
         s2pp_map, nsym_list = get_nsym_list_and_s2pp(s2p_map, p2p_map, permutations)
-
-        permutations = np.array(permutations, dtype="int64", order="C")
-        s2pp_map = np.array(s2pp_map, dtype="int64")
-        p2s_map = np.array(p2s_map, dtype="int64")
-        nsym_list = np.array(nsym_list, dtype="int64")
         phono3c.transpose_compact_fc3(
             fc3, permutations, s2pp_map, p2s_map, nsym_list, 0
         )  # dim[0] <--> dim[1]
@@ -628,10 +623,6 @@ def get_drift_fc3(
             p2p_map = primitive.p2p_map
             permutations = primitive.atomic_permutations
             s2pp_map, nsym_list = get_nsym_list_and_s2pp(s2p_map, p2p_map, permutations)
-            permutations = np.array(permutations, dtype="int64", order="C")
-            s2pp_map = np.array(s2pp_map, dtype="int64")
-            p2s_map = np.array(p2s_map, dtype="int64")
-            nsym_list = np.array(nsym_list, dtype="int64")
             num_patom = fc3.shape[0]
             num_satom = fc3.shape[1]
             maxval1 = 0

phono3py/phonon3/interaction.py

@@ -174,8 +174,8 @@ def __init__(
 
         self._svecs, self._multi = self._primitive.get_smallest_vectors()
         self._masses = np.array(self._primitive.masses, dtype="double")
-        self._p2s = np.array(self._primitive.p2s_map, dtype="int64")
-        self._s2p = np.array(self._primitive.s2p_map, dtype="int64")
+        self._p2s = self._primitive.p2s_map
+        self._s2p = self._primitive.s2p_map
         n_satom, n_patom, _ = self._multi.shape
         self._all_shortest = np.zeros(
             (n_patom, n_satom, n_satom), dtype="byte", order="C"
@@ -680,7 +680,7 @@ def run_phonon_solver_with_eigvec_rotation(self):
 
         d2r_map = self._get_reciprocal_rotations_in_space_group_operations()
 
-        # perms.shape = (len(spg_ops), len(primitive)), dtype='intc'
+        # perms.shape = (len(spg_ops), len(primitive)), dtype='int64'
         perms = compute_all_sg_permutations(
             self._primitive.scaled_positions,
             self._bz_grid.symmetry_dataset.rotations,  # type: ignore