Fix nearest neighbor index errors/Remove SciPy upper limit (#2475)

* Add fix, remove SciPy upper limit

* Add changelog

changelog/2475.trivial.rst

@@ -0,0 +1 @@
+Changed ``_nearest_neighbor_interpolator`` method in `~plasmapy.plasma.grids` to interpolate quantities array instead of producing an intermediate index.

plasmapy/plasma/grids.py

@@ -1393,9 +1393,9 @@ def _nearest_neighbor_interpolator(self):
 
         """
 
-        indgrid = np.arange(self.grid.shape[0])
-
-        return interp.NearestNDInterpolator(self.grid.to(u.m).value, indgrid)
+        return interp.NearestNDInterpolator(
+            self.grid.to(u.m).value, self._interp_quantities
+        )
 
     @modify_docstring(prepend=AbstractGrid.nearest_neighbor_interpolator.__doc__)
     def nearest_neighbor_interpolator(
@@ -1418,10 +1418,6 @@ def nearest_neighbor_interpolator(
         pts1 = self.pts1.to(u.m).value
         pts2 = self.pts2.to(u.m).value
 
-        i = self._nearest_neighbor_interpolator(pos)
-
-        vals = self._interp_quantities[i, :]
-
         mask_particle_off = (
             (pos[:, 0] < pts0.min())
             | (pos[:, 0] > pts0.max())
@@ -1431,6 +1427,7 @@ def nearest_neighbor_interpolator(
             | (pos[:, 2] > pts2.max())
         )
 
+        vals = self._nearest_neighbor_interpolator(pos)
         vals[mask_particle_off] = np.nan
 
         output = [vals[:, arg] * self._interp_units[arg] for arg in range(len(args))]

pyproject.toml

@@ -50,7 +50,7 @@ dependencies = [
   "pandas >= 1.3.0",
   "pytest >= 7.0.1",
   "requests >= 2.27.1",
-  "scipy >= 1.7.0, < 1.12.0",
+  "scipy >= 1.7.0",
   "tqdm >= 4.60.0",
   "voila >= 0.5.0",
   "wrapt >= 1.12.1",