refactor: extract autograd constants to dedicated module

- Create tidy3d/components/autograd/constants.py
- Move MAX_NUM_TRACED_STRUCTURES and MAX_NUM_ADJOINT_PER_FWD from autograd.py
- Move PTS_PER_WVL_MAT_CYLINDER_DISCRETIZE from primitives.py

Author: yaugenst-flex

tests/test_components/test_autograd.py

@@ -19,13 +19,13 @@
 
 import tidy3d as td
 import tidy3d.web as web
+from tidy3d.components.autograd.constants import MAX_NUM_TRACED_STRUCTURES
 from tidy3d.components.autograd.derivative_utils import DerivativeInfo
 from tidy3d.components.autograd.utils import is_tidy_box
 from tidy3d.components.data.data_array import DataArray
 from tidy3d.exceptions import AdjointError
 from tidy3d.plugins.polyslab import ComplexPolySlab
 from tidy3d.web import run, run_async
-from tidy3d.web.api.autograd.autograd import MAX_NUM_TRACED_STRUCTURES
 from tidy3d.web.api.autograd.utils import FieldMap
 
 from ..utils import SIM_FULL, AssertLogLevel, run_emulated, tracer_arr

tidy3d/components/autograd/constants.py

@@ -0,0 +1,8 @@
+# interval space for adjoint monitors (half of sim resolution)
+from __future__ import annotations
+
+# default number of points per wvl in material for discretizing cylinder in autograd derivative
+PTS_PER_WVL_MAT_CYLINDER_DISCRETIZE = 10
+
+MAX_NUM_TRACED_STRUCTURES = 500
+MAX_NUM_ADJOINT_PER_FWD = 10

tidy3d/components/geometry/primitives.py

@@ -11,6 +11,7 @@
 import shapely
 
 from tidy3d.components.autograd import AutogradFieldMap, TracedSize1D
+from tidy3d.components.autograd.constants import PTS_PER_WVL_MAT_CYLINDER_DISCRETIZE
 from tidy3d.components.autograd.derivative_utils import DerivativeInfo
 from tidy3d.components.base import cached_property, skip_if_fields_missing
 from tidy3d.components.types import Axis, Bound, Coordinate, MatrixReal4x4, Shapely
@@ -30,9 +31,6 @@
 # Default number of points to discretize polyslab in `Cylinder.to_polyslab()`
 _N_PTS_CYLINDER_POLYSLAB = 51
 
-# Default number of points per wvl in material for discretizing cylinder in autograd derivative
-_PTS_PER_WVL_MAT_CYLINDER_DISCRETIZE = 10
-
 
 class Sphere(base.Centered, base.Circular):
     """Spherical geometry.
@@ -291,7 +289,7 @@ def _compute_derivatives(self, derivative_info: DerivativeInfo) -> AutogradField
         wvls_in_circumference = circumference / wvl_mat
 
         num_pts_circumference = int(
-            np.ceil(_PTS_PER_WVL_MAT_CYLINDER_DISCRETIZE * wvls_in_circumference)
+            np.ceil(PTS_PER_WVL_MAT_CYLINDER_DISCRETIZE * wvls_in_circumference)
         )
         num_pts_circumference = max(3, num_pts_circumference)
 

tidy3d/web/api/autograd/autograd.py

@@ -14,6 +14,7 @@
 
 import tidy3d as td
 from tidy3d.components.autograd import AutogradFieldMap, get_static
+from tidy3d.components.autograd.constants import MAX_NUM_ADJOINT_PER_FWD, MAX_NUM_TRACED_STRUCTURES
 from tidy3d.components.autograd.derivative_utils import DerivativeInfo
 from tidy3d.exceptions import AdjointError
 from tidy3d.web.api.asynchronous import DEFAULT_DATA_DIR
@@ -35,9 +36,6 @@
 SIM_VJP_FILE = "output/autograd_sim_vjp.hdf5"
 SIM_FIELDS_KEYS_FILE = "autograd_sim_fields_keys.hdf5"
 
-MAX_NUM_TRACED_STRUCTURES = 500
-MAX_NUM_ADJOINT_PER_FWD = 10
-
 # default value for whether to do local gradient calculation (True) or server side (False)
 LOCAL_GRADIENT = False