fix: Unit conversion of LazyValueRange.

The unit conversion was indeed botched, with a typo causing the start of
the range to be converted as if it were the end of the range.

Closes #3.

TODO.md

@@ -510,7 +510,7 @@ Header color style can't be done, unfortunately. Body color feels unclean, so no
 
 ## BLCache
 - [ ] Replace every raw property with `BLField`.
-- [ ] Add matrix property support: https://developer.blender.org/docs/release_notes/3.0/python_api/#other-additions
+- [x] Add matrix property support: https://developer.blender.org/docs/release_notes/3.0/python_api/#other-additions
 - [ ] Fix many problems by persisting `_enum_cb_cache` and `_str_cb_cache`.
 - [ ] Docstring parser for descriptions.
 - [ ] Method of dynamically setting property options after creation, using `idproperty_ui_data`
@@ -524,6 +524,10 @@ We're trying to do our part by reporting bugs we find!
 This is where we keep track of them for now, if they're not covered by the above listings.
 
 ## Blender Maxwell Bugs
+See Issues.
+
+## Testing
+- [ ] `pytest` integration exhibits a bootstrapping problem when using https://github.com/mondeja/pytest-blender
 
 ## Blender Bugs
 Reported:
@@ -545,6 +549,7 @@ Unreported:
 ## Tidy3D bugs
 Unreported:
 - Directly running `SimulationTask.get()` is missing fields - it doesn't return some fields, including `created_at`. Listing tasks by folder is not broken.
+- Frequency ranges don't check for repeated elements.
 
 
 

pyproject.toml

@@ -39,7 +39,8 @@ managed = true
 virtual = true
 dev-dependencies = [
     "ruff>=0.3.2",
-    "fake-bpy-module-4-0>=20231118",  ## TODO: Update to Blender 4.1.0
+    "fake-bpy-module-4-0>=20231118",
+    ## TODO: Update to Blender 4.1.0
 ]
 
 [tool.rye.scripts]
@@ -143,3 +144,9 @@ max-args = 6
 quote-style = "single"
 indent-style = "tab"
 docstring-code-format = false
+
+####################
+# - Tooling: Pytest
+####################
+#[tool.pytest.ini_options]
+

src/blender_maxwell/node_trees/maxwell_sim_nodes/contracts/flow_kinds/__init__.py

@@ -0,0 +1,19 @@
+from .array import ArrayFlow
+from .capabilities import CapabilitiesFlow
+from .flow_kinds import FlowKind
+from .info import InfoFlow
+from .lazy_array_range import LazyArrayRangeFlow
+from .lazy_value_func import LazyValueFuncFlow
+from .params import ParamsFlow
+from .value import ValueFlow
+
+__all__ = [
+	'ArrayFlow',
+	'CapabilitiesFlow',
+	'FlowKind',
+	'InfoFlow',
+	'LazyArrayRangeFlow',
+	'LazyValueFuncFlow',
+	'ParamsFlow',
+	'ValueFlow',
+]

src/blender_maxwell/node_trees/maxwell_sim_nodes/contracts/flow_kinds/array.py

@@ -0,0 +1,96 @@
+import dataclasses
+import functools
+import typing as typ
+
+import jaxtyping as jtyp
+import numpy as np
+import sympy.physics.units as spu
+
+from blender_maxwell.utils import extra_sympy_units as spux
+from blender_maxwell.utils import logger
+
+log = logger.get(__name__)
+
+
+@dataclasses.dataclass(frozen=True, kw_only=True)
+class ArrayFlow:
+	"""A simple, flat array of values with an optionally-attached unit.
+
+	Attributes:
+		values: An ND array-like object of arbitrary numerical type.
+		unit: A `sympy` unit.
+			None if unitless.
+	"""
+
+	values: jtyp.Shaped[jtyp.Array, '...']
+	unit: spux.Unit | None = None
+
+	is_sorted: bool = False
+
+	def __len__(self) -> int:
+		return len(self.values)
+
+	@functools.cached_property
+	def mathtype(self) -> spux.MathType:
+		return spux.MathType.from_pytype(type(self.values.item(0)))
+
+	def nearest_idx_of(self, value: spux.SympyType, require_sorted: bool = True) -> int:
+		"""Find the index of the value that is closest to the given value.
+
+		Units are taken into account; the given value will be scaled to the internal unit before direct use.
+
+		Parameters:
+			require_sorted: Require that `self.values` be sorted, so that use of the faster binary-search algorithm is guaranteed.
+
+		Returns:
+			The index of `self.values` that is closest to the value `value`.
+		"""
+		if not require_sorted:
+			raise NotImplementedError
+
+		# Scale Given Value to Internal Unit
+		scaled_value = spux.sympy_to_python(spux.scale_to_unit(value, self.unit))
+
+		# BinSearch for "Right IDX"
+		## >>> self.values[right_idx] > scaled_value
+		## >>> self.values[right_idx - 1] < scaled_value
+		right_idx = np.searchsorted(self.values, scaled_value, side='left')
+
+		# Case: Right IDX is Boundary
+		if right_idx == 0:
+			return right_idx
+		if right_idx == len(self.values):
+			return right_idx - 1
+
+		# Find Closest of [Right IDX - 1, Right IDX]
+		left_val = self.values[right_idx - 1]
+		right_val = self.values[right_idx]
+
+		if (scaled_value - left_val) <= (right_val - scaled_value):
+			return right_idx - 1
+
+		return right_idx
+
+	def correct_unit(self, corrected_unit: spu.Quantity) -> typ.Self:
+		if self.unit is not None:
+			return ArrayFlow(
+				values=self.values, unit=corrected_unit, is_sorted=self.is_sorted
+			)
+
+		msg = f'Tried to correct unit of unitless LazyDataValueRange "{corrected_unit}"'
+		raise ValueError(msg)
+
+	def rescale_to_unit(self, unit: spu.Quantity) -> typ.Self:
+		if self.unit is not None:
+			return ArrayFlow(
+				values=float(spux.scaling_factor(self.unit, unit)) * self.values,
+				unit=unit,
+				is_sorted=self.is_sorted,  ## TODO: Can we really say that?
+			)
+			## TODO: Is this scaling numerically stable?
+
+		msg = f'Tried to rescale unitless LazyDataValueRange to unit {unit}'
+		raise ValueError(msg)
+
+	def rescale_to_unit_system(self, unit: spu.Quantity) -> typ.Self:
+		raise NotImplementedError

src/blender_maxwell/node_trees/maxwell_sim_nodes/contracts/flow_kinds/capabilities.py

@@ -0,0 +1,39 @@
+import dataclasses
+import typing as typ
+
+from ..socket_types import SocketType
+from .flow_kinds import FlowKind
+
+
+@dataclasses.dataclass(frozen=True, kw_only=True)
+class CapabilitiesFlow:
+	socket_type: SocketType
+	active_kind: FlowKind
+
+	is_universal: bool = False
+
+	# == Constraint
+	must_match: dict[str, typ.Any] = dataclasses.field(default_factory=dict)
+
+	# ∀b (b ∈ A) Constraint
+	## A: allow_any
+	## b∈B: present_any
+	allow_any: set[typ.Any] = dataclasses.field(default_factory=set)
+	present_any: set[typ.Any] = dataclasses.field(default_factory=set)
+
+	def is_compatible_with(self, other: typ.Self) -> bool:
+		return other.is_universal or (
+			self.socket_type == other.socket_type
+			and self.active_kind == other.active_kind
+			# == Constraint
+			and all(
+				name in other.must_match
+				and self.must_match[name] == other.must_match[name]
+				for name in self.must_match
+			)
+			# ∀b (b ∈ A) Constraint
+			and (
+				self.present_any & other.allow_any
+				or (not self.present_any and not self.allow_any)
+			)
+		)

src/blender_maxwell/node_trees/maxwell_sim_nodes/contracts/flow_kinds/flow_kinds.py

@@ -0,0 +1,70 @@
+import enum
+import typing as typ
+
+from blender_maxwell.utils import extra_sympy_units as spux
+from blender_maxwell.utils import logger
+
+log = logger.get(__name__)
+
+
+class FlowKind(enum.StrEnum):
+	"""Defines a kind of data that can flow between nodes.
+
+	Each node link can be thought to contain **multiple pipelines for data to flow along**.
+	Each pipeline is cached incrementally, and independently, of the others.
+	Thus, the same socket can easily support several kinds of related data flow at the same time.
+
+	Attributes:
+		Capabilities: Describes a socket's linkeability with other sockets.
+			Links between sockets with incompatible capabilities will be rejected.
+			This doesn't need to be defined normally, as there is a default.
+			However, in some cases, defining it manually to control linkeability more granularly may be desirable.
+		Value: A generic object, which is "directly usable".
+			This should be chosen when a more specific flow kind doesn't apply.
+		Array: An object with dimensions, and possibly a unit.
+			Whenever a `Value` is defined, a single-element `list` will also be generated by default as `Array`
+			However, for any other array-like variants (or sockets that only represent array-like objects), `Array` should be defined manually.
+		LazyValueFunc: A composable function.
+			Can be used to represent computations for which all data is not yet known, or for which just-in-time compilation can drastically increase performance.
+		LazyArrayRange: An object that generates an `Array` from range information (start/stop/step/spacing).
+			This should be used instead of `Array` whenever possible.
+		Param: A dictionary providing particular parameters for a lazy value.
+		Info: An dictionary providing extra context about any aspect of flow.
+	"""
+
+	Capabilities = enum.auto()
+
+	# Values
+	Value = enum.auto()
+	Array = enum.auto()
+
+	# Lazy
+	LazyValueFunc = enum.auto()
+	LazyArrayRange = enum.auto()
+
+	# Auxiliary
+	Params = enum.auto()
+	Info = enum.auto()
+
+	@classmethod
+	def scale_to_unit_system(
+		cls,
+		kind: typ.Self,
+		flow_obj,
+		unit_system: spux.UnitSystem,
+	):
+		log.debug('%s: Scaling "%s" to Unit System', kind, str(flow_obj))
+		if kind == FlowKind.Value:
+			return spux.scale_to_unit_system(
+				flow_obj,
+				unit_system,
+			)
+		if kind == FlowKind.LazyArrayRange:
+			log.debug([kind, flow_obj, unit_system])
+			return flow_obj.rescale_to_unit_system(unit_system)
+
+		if kind == FlowKind.Params:
+			return flow_obj.rescale_to_unit_system(unit_system)
+
+		msg = 'Tried to scale unknown kind'
+		raise ValueError(msg)

src/blender_maxwell/node_trees/maxwell_sim_nodes/contracts/flow_kinds/info.py

@@ -0,0 +1,182 @@
+import dataclasses
+import functools
+import typing as typ
+
+import jax
+
+from blender_maxwell.utils import extra_sympy_units as spux
+from blender_maxwell.utils import logger
+
+from .array import ArrayFlow
+from .lazy_array_range import LazyArrayRangeFlow
+
+log = logger.get(__name__)
+
+
+@dataclasses.dataclass(frozen=True, kw_only=True)
+class InfoFlow:
+	# Dimension Information
+	dim_names: list[str] = dataclasses.field(default_factory=list)
+	dim_idx: dict[str, ArrayFlow | LazyArrayRangeFlow] = dataclasses.field(
+		default_factory=dict
+	)  ## TODO: Rename to dim_idxs
+
+	@functools.cached_property
+	def dim_lens(self) -> dict[str, int]:
+		return {dim_name: len(dim_idx) for dim_name, dim_idx in self.dim_idx.items()}
+
+	@functools.cached_property
+	def dim_mathtypes(self) -> dict[str, spux.MathType]:
+		return {
+			dim_name: dim_idx.mathtype for dim_name, dim_idx in self.dim_idx.items()
+		}
+
+	@functools.cached_property
+	def dim_units(self) -> dict[str, spux.Unit]:
+		return {dim_name: dim_idx.unit for dim_name, dim_idx in self.dim_idx.items()}
+
+	@functools.cached_property
+	def dim_physical_types(self) -> dict[str, spux.PhysicalType]:
+		return {
+			dim_name: spux.PhysicalType.from_unit(dim_idx.unit)
+			for dim_name, dim_idx in self.dim_idx.items()
+		}
+
+	@functools.cached_property
+	def dim_idx_arrays(self) -> list[jax.Array]:
+		return [
+			dim_idx.realize().values
+			if isinstance(dim_idx, LazyArrayRangeFlow)
+			else dim_idx.values
+			for dim_idx in self.dim_idx.values()
+		]
+
+	# Output Information
+	## TODO: Add PhysicalType
+	output_name: str = dataclasses.field(default_factory=list)
+	output_shape: tuple[int, ...] | None = dataclasses.field(default=None)
+	output_mathtype: spux.MathType = dataclasses.field()
+	output_unit: spux.Unit | None = dataclasses.field()
+
+	# Pinned Dimension Information
+	## TODO: Add PhysicalType
+	pinned_dim_names: list[str] = dataclasses.field(default_factory=list)
+	pinned_dim_values: dict[str, float | complex] = dataclasses.field(
+		default_factory=dict
+	)
+	pinned_dim_mathtypes: dict[str, spux.MathType] = dataclasses.field(
+		default_factory=dict
+	)
+	pinned_dim_units: dict[str, spux.Unit] = dataclasses.field(default_factory=dict)
+
+	####################
+	# - Methods
+	####################
+	def rescale_dim_idxs(self, new_dim_idxs: dict[str, LazyArrayRangeFlow]) -> typ.Self:
+		return InfoFlow(
+			# Dimensions
+			dim_names=self.dim_names,
+			dim_idx={
+				_dim_name: new_dim_idxs.get(_dim_name, dim_idx)
+				for _dim_name, dim_idx in self.dim_idx.items()
+			},
+			# Outputs
+			output_name=self.output_name,
+			output_shape=self.output_shape,
+			output_mathtype=self.output_mathtype,
+			output_unit=self.output_unit,
+		)
+
+	def delete_dimension(self, dim_name: str) -> typ.Self:
+		"""Delete a dimension."""
+		return InfoFlow(
+			# Dimensions
+			dim_names=[
+				_dim_name for _dim_name in self.dim_names if _dim_name != dim_name
+			],
+			dim_idx={
+				_dim_name: dim_idx
+				for _dim_name, dim_idx in self.dim_idx.items()
+				if _dim_name != dim_name
+			},
+			# Outputs
+			output_name=self.output_name,
+			output_shape=self.output_shape,
+			output_mathtype=self.output_mathtype,
+			output_unit=self.output_unit,
+		)
+
+	def swap_dimensions(self, dim_0_name: str, dim_1_name: str) -> typ.Self:
+		"""Delete a dimension."""
+
+		# Compute Swapped Dimension Name List
+		def name_swapper(dim_name):
+			return (
+				dim_name
+				if dim_name not in [dim_0_name, dim_1_name]
+				else {dim_0_name: dim_1_name, dim_1_name: dim_0_name}[dim_name]
+			)
+
+		dim_names = [name_swapper(dim_name) for dim_name in self.dim_names]
+
+		# Compute Info
+		return InfoFlow(
+			# Dimensions
+			dim_names=dim_names,
+			dim_idx={dim_name: self.dim_idx[dim_name] for dim_name in dim_names},
+			# Outputs
+			output_name=self.output_name,
+			output_shape=self.output_shape,
+			output_mathtype=self.output_mathtype,
+			output_unit=self.output_unit,
+		)
+
+	def set_output_mathtype(self, output_mathtype: spux.MathType) -> typ.Self:
+		"""Set the MathType of a particular output name."""
+		return InfoFlow(
+			dim_names=self.dim_names,
+			dim_idx=self.dim_idx,
+			# Outputs
+			output_name=self.output_name,
+			output_shape=self.output_shape,
+			output_mathtype=output_mathtype,
+			output_unit=self.output_unit,
+		)
+
+	def collapse_output(
+		self,
+		collapsed_name: str,
+		collapsed_mathtype: spux.MathType,
+		collapsed_unit: spux.Unit,
+	) -> typ.Self:
+		return InfoFlow(
+			# Dimensions
+			dim_names=self.dim_names,
+			dim_idx=self.dim_idx,
+			output_name=collapsed_name,
+			output_shape=None,
+			output_mathtype=collapsed_mathtype,
+			output_unit=collapsed_unit,
+		)
+
+	@functools.cached_property
+	def shift_last_input(self):
+		"""Shift the last input dimension to the output."""
+		return InfoFlow(
+			# Dimensions
+			dim_names=self.dim_names[:-1],
+			dim_idx={
+				dim_name: dim_idx
+				for dim_name, dim_idx in self.dim_idx.items()
+				if dim_name != self.dim_names[-1]
+			},
+			# Outputs
+			output_name=self.output_name,
+			output_shape=(
+				(self.dim_lens[self.dim_names[-1]],)
+				if self.output_shape is None
+				else (self.dim_lens[self.dim_names[-1]], *self.output_shape)
+			),
+			output_mathtype=self.output_mathtype,
+			output_unit=self.output_unit,
+		)

src/blender_maxwell/node_trees/maxwell_sim_nodes/contracts/flow_kinds/lazy_array_range.py

@@ -0,0 +1,385 @@
+import dataclasses
+import functools
+import typing as typ
+from types import MappingProxyType
+
+import jax.numpy as jnp
+import jaxtyping as jtyp
+import sympy as sp
+
+from blender_maxwell.utils import extra_sympy_units as spux
+from blender_maxwell.utils import logger
+
+from .array import ArrayFlow
+from .flow_kinds import FlowKind
+from .lazy_value_func import LazyValueFuncFlow
+
+log = logger.get(__name__)
+
+
+@dataclasses.dataclass(frozen=True, kw_only=True)
+class LazyArrayRangeFlow:
+	r"""Represents a linearly/logarithmically spaced array using symbolic boundary expressions, with support for units and lazy evaluation.
+
+	# Advantages
+	Whenever an array can be represented like this, the advantages over an `ArrayFlow` are numerous.
+
+	## Memory
+	`ArrayFlow` generally has a memory scaling of $O(n)$.
+	Naturally, `LazyArrayRangeFlow` is always constant, since only the boundaries and steps are stored.
+
+	## Symbolic
+	Both boundary points are symbolic expressions, within which pre-defined `sp.Symbol`s can participate in a constrained manner (ex. an integer symbol).
+
+	One need not know the value of the symbols immediately - such decisions can be deferred until later in the computational flow.
+
+	## Performant Unit-Aware Operations
+	While `ArrayFlow`s are also unit-aware, the time-cost of _any_ unit-scaling operation scales with $O(n)$.
+	`LazyArrayRangeFlow`, by contrast, scales as $O(1)$.
+
+	As a result, more complicated operations (like symbolic or unit-based) that might be difficult to perform interactively in real-time on an `ArrayFlow` will work perfectly with this object, even with added complexity
+
+	## High-Performance Composition and Gradiant
+	With `self.as_func`, a `jax` function is produced that generates the array according to the symbolic `start`, `stop` and `steps`.
+	There are two nice things about this:
+
+	- **Gradient**: The gradient of the output array, with respect to any symbols used to define the input bounds, can easily be found using `jax.grad` over `self.as_func`.
+	- **JIT**: When `self.as_func` is composed with other `jax` functions, and `jax.jit` is run to optimize the entire thing, the "cost of array generation" _will often be optimized away significantly or entirely_.
+
+	Thus, as part of larger computations, the performance properties of `LazyArrayRangeFlow` is extremely favorable.
+
+	## Numerical Properties
+	Since the bounds support exact (ex. rational) calculations and symbolic manipulations (_by virtue of being symbolic expressions_), the opportunities for certain kinds of numerical instability are mitigated.
+
+	Attributes:
+		start: An expression generating a scalar, unitless, complex value for the array's lower bound.
+			_Integer, rational, and real values are also supported._
+		stop: An expression generating a scalar, unitless, complex value for the array's upper bound.
+			_Integer, rational, and real values are also supported._
+		steps: The amount of steps (**inclusive**) to generate from `start` to `stop`.
+		scaling: The method of distributing `step` values between the two endpoints.
+			Generally, the linear default is sufficient.
+
+		unit: The unit of the generated array values
+
+		symbols: Set of variables from which `start` and/or `stop` are determined.
+	"""
+
+	start: spux.ScalarUnitlessComplexExpr
+	stop: spux.ScalarUnitlessComplexExpr
+	steps: int
+	scaling: typ.Literal['lin', 'geom', 'log'] = 'lin'
+
+	unit: spux.Unit | None = None
+
+	symbols: frozenset[spux.IntSymbol] = frozenset()
+
+	@functools.cached_property
+	def sorted_symbols(self) -> list[sp.Symbol]:
+		"""Retrieves all symbols by concatenating int, real, and complex symbols, and sorting them by name.
+
+		The order is guaranteed to be **deterministic**.
+
+		Returns:
+			All symbols valid for use in the expression.
+		"""
+		return sorted(self.symbols, key=lambda sym: sym.name)
+
+	@functools.cached_property
+	def mathtype(self) -> spux.MathType:
+		"""Conservatively compute the most stringent `spux.MathType` that can represent both `self.start` and `self.stop`.
+
+		Notes:
+			The mathtype is determined from start/stop either using `sympy` assumptions, or as Python types.
+
+			For precise information on how start/stop are "combined", see `spux.MathType.combine()`.
+
+		Returns:
+			All symbols valid for use in the expression.
+		"""
+		# Get Start Mathtype
+		if isinstance(self.start, spux.SympyType):
+			start_mathtype = spux.MathType.from_expr(self.start)
+		else:
+			start_mathtype = spux.MathType.from_pytype(type(self.start))
+
+		# Get Stop Mathtype
+		if isinstance(self.stop, spux.SympyType):
+			stop_mathtype = spux.MathType.from_expr(self.stop)
+		else:
+			stop_mathtype = spux.MathType.from_pytype(type(self.stop))
+
+		# Check Equal
+		combined_mathtype = spux.MathType.combine(start_mathtype, stop_mathtype)
+		log.debug(
+			'%s: Computed MathType as %s (start_mathtype=%s, stop_mathtype=%s)',
+			self,
+			combined_mathtype,
+			start_mathtype,
+			stop_mathtype,
+		)
+		return combined_mathtype
+
+	def __len__(self):
+		"""Compute the length of the array to be realized.
+
+		Returns:
+			The number of steps.
+		"""
+		return self.steps
+
+	####################
+	# - Units
+	####################
+	def correct_unit(self, corrected_unit: spux.Unit) -> typ.Self:
+		"""Replaces the unit without rescaling the unitless bounds.
+
+		Parameters:
+			corrected_unit: The unit to replace the current unit with.
+
+		Returns:
+			A new `LazyArrayRangeFlow` with replaced unit.
+
+		Raises:
+			ValueError: If the existing unit is `None`, indicating that there is no unit to correct.
+		"""
+		if self.unit is not None:
+			log.debug(
+				'%s: Corrected unit to %s',
+				self,
+				corrected_unit,
+			)
+			return LazyArrayRangeFlow(
+				start=self.start,
+				stop=self.stop,
+				steps=self.steps,
+				scaling=self.scaling,
+				unit=corrected_unit,
+				symbols=self.symbols,
+			)
+
+		msg = f'Tried to correct unit of unitless LazyDataValueRange "{corrected_unit}"'
+		raise ValueError(msg)
+
+	def rescale_to_unit(self, unit: spux.Unit) -> typ.Self:
+		"""Replaces the unit, **with** rescaling of the bounds.
+
+		Parameters:
+			unit: The unit to convert the bounds to.
+
+		Returns:
+			A new `LazyArrayRangeFlow` with replaced unit.
+
+		Raises:
+			ValueError: If the existing unit is `None`, indicating that there is no unit to correct.
+		"""
+		if self.unit is not None:
+			log.debug(
+				'%s: Scaled to unit %s',
+				self,
+				unit,
+			)
+			return LazyArrayRangeFlow(
+				start=spux.scale_to_unit(self.start * self.unit, unit),
+				stop=spux.scale_to_unit(self.stop * self.unit, unit),
+				steps=self.steps,
+				scaling=self.scaling,
+				unit=unit,
+				symbols=self.symbols,
+			)
+
+		msg = f'Tried to rescale unitless LazyDataValueRange to unit {unit}'
+		raise ValueError(msg)
+
+	def rescale_to_unit_system(self, unit_system: spux.Unit) -> typ.Self:
+		"""Replaces the units, **with** rescaling of the bounds.
+
+		Parameters:
+			unit: The unit to convert the bounds to.
+
+		Returns:
+			A new `LazyArrayRangeFlow` with replaced unit.
+
+		Raises:
+			ValueError: If the existing unit is `None`, indicating that there is no unit to correct.
+		"""
+		if self.unit is not None:
+			log.debug(
+				'%s: Scaled to unit system: %s',
+				self,
+				str(unit_system),
+			)
+			return LazyArrayRangeFlow(
+				start=spux.strip_unit_system(
+					spux.convert_to_unit_system(self.start * self.unit, unit_system),
+					unit_system,
+				),
+				stop=spux.strip_unit_system(
+					spux.convert_to_unit_system(self.stop * self.unit, unit_system),
+					unit_system,
+				),
+				steps=self.steps,
+				scaling=self.scaling,
+				unit=unit_system[spux.PhysicalType.from_unit(self.unit)],
+				symbols=self.symbols,
+			)
+
+		msg = (
+			f'Tried to rescale unitless LazyDataValueRange to unit system {unit_system}'
+		)
+		raise ValueError(msg)
+
+	####################
+	# - Bound Operations
+	####################
+	def rescale_bounds(
+		self,
+		rescale_func: typ.Callable[
+			[spux.ScalarUnitlessComplexExpr], spux.ScalarUnitlessComplexExpr
+		],
+		reverse: bool = False,
+	) -> typ.Self:
+		"""Apply a function to the bounds, effectively rescaling the represented array.
+
+		Notes:
+			**It is presumed that the bounds are scaled with the same factor**.
+			Breaking this presumption may have unexpected results.
+
+			The scalar, unitless, complex-valuedness of the bounds must also be respected; additionally, new symbols must not be introduced.
+
+		Parameters:
+			scaler: The function that scales each bound.
+			reverse: Whether to reverse the bounds after running the `scaler`.
+
+		Returns:
+			A rescaled `LazyArrayRangeFlow`.
+		"""
+		return LazyArrayRangeFlow(
+			start=rescale_func(self.start if not reverse else self.stop),
+			stop=rescale_func(self.stop if not reverse else self.start),
+			steps=self.steps,
+			scaling=self.scaling,
+			unit=self.unit,
+			symbols=self.symbols,
+		)
+
+	####################
+	# - Lazy Representation
+	####################
+	@functools.cached_property
+	def array_generator(
+		self,
+	) -> typ.Callable[
+		[int | float | complex, int | float | complex, int],
+		jtyp.Inexact[jtyp.Array, ' steps'],
+	]:
+		"""Compute the correct `jnp.*space` array generator, where `*` is one of the supported scaling methods.
+
+		Returns:
+			A `jax` function that takes a valid `start`, `stop`, and `steps`, and returns a 1D `jax` array.
+		"""
+		jnp_nspace = {
+			'lin': jnp.linspace,
+			'geom': jnp.geomspace,
+			'log': jnp.logspace,
+		}.get(self.scaling)
+		if jnp_nspace is None:
+			msg = f'ArrayFlow scaling method {self.scaling} is unsupported'
+			raise RuntimeError(msg)
+
+		return jnp_nspace
+
+	@functools.cached_property
+	def as_func(
+		self,
+	) -> typ.Callable[[int | float | complex, ...], jtyp.Inexact[jtyp.Array, ' steps']]:
+		"""Create a function that can compute the non-lazy output array as a function of the symbols in the expressions for `start` and `stop`.
+
+		Notes:
+			The ordering of the symbols is identical to `self.symbols`, which is guaranteed to be a deterministically sorted list of symbols.
+
+		Returns:
+			A `LazyValueFuncFlow` that, given the input symbols defined in `self.symbols`,
+		"""
+		# Compile JAX Functions for Start/End Expressions
+		## FYI, JAX-in-JAX works perfectly fine.
+		start_jax = sp.lambdify(self.symbols, self.start, 'jax')
+		stop_jax = sp.lambdify(self.symbols, self.stop, 'jax')
+
+		# Compile ArrayGen Function
+		def gen_array(
+			*args: list[int | float | complex],
+		) -> jtyp.Inexact[jtyp.Array, ' steps']:
+			return self.array_generator(start_jax(*args), stop_jax(*args), self.steps)
+
+		# Return ArrayGen Function
+		return gen_array
+
+	@functools.cached_property
+	def as_lazy_value_func(self) -> LazyValueFuncFlow:
+		"""Creates a `LazyValueFuncFlow` using the output of `self.as_func`.
+
+		This is useful for ex. parameterizing the first array in the node graph, without binding an entire computed array.
+
+		Notes:
+			The the function enclosed in the `LazyValueFuncFlow` is identical to the one returned by `self.as_func`.
+
+		Returns:
+			A `LazyValueFuncFlow` containing `self.as_func`, as well as appropriate supporting settings.
+		"""
+		return LazyValueFuncFlow(
+			func=self.as_func,
+			func_args=[(spux.MathType.from_expr(sym)) for sym in self.symbols],
+			supports_jax=True,
+		)
+
+	####################
+	# - Realization
+	####################
+	def realize(
+		self,
+		symbol_values: dict[spux.Symbol, typ.Any] = MappingProxyType({}),
+		kind: typ.Literal[FlowKind.Array, FlowKind.LazyValueFunc] = FlowKind.Array,
+	) -> ArrayFlow | LazyValueFuncFlow:
+		"""Apply a function to the bounds, effectively rescaling the represented array.
+
+		Notes:
+			**It is presumed that the bounds are scaled with the same factor**.
+			Breaking this presumption may have unexpected results.
+
+			The scalar, unitless, complex-valuedness of the bounds must also be respected; additionally, new symbols must not be introduced.
+
+		Parameters:
+			scaler: The function that scales each bound.
+			reverse: Whether to reverse the bounds after running the `scaler`.
+
+		Returns:
+			A rescaled `LazyArrayRangeFlow`.
+		"""
+		if not set(self.symbols).issubset(set(symbol_values.keys())):
+			msg = f'Provided symbols ({set(symbol_values.keys())}) do not provide values for all expression symbols ({self.symbols}) that may be found in the boundary expressions (start={self.start}, end={self.end})'
+			raise ValueError(msg)
+
+		# Realize Symbols
+		realized_start = spux.sympy_to_python(
+			self.start.subs({sym: symbol_values[sym.name] for sym in self.symbols})
+		)
+		realized_stop = spux.sympy_to_python(
+			self.stop.subs({sym: symbol_values[sym.name] for sym in self.symbols})
+		)
+
+		# Return Linspace / Logspace
+		def gen_array() -> jtyp.Inexact[jtyp.Array, ' steps']:
+			return self.array_generator(realized_start, realized_stop, self.steps)
+
+		if kind == FlowKind.Array:
+			return ArrayFlow(values=gen_array(), unit=self.unit, is_sorted=True)
+		if kind == FlowKind.LazyValueFunc:
+			return LazyValueFuncFlow(func=gen_array, supports_jax=True)
+
+		msg = f'Invalid kind: {kind}'
+		raise TypeError(msg)
+
+	@functools.cached_property
+	def realize_array(self) -> ArrayFlow:
+		return self.realize()

src/blender_maxwell/node_trees/maxwell_sim_nodes/contracts/flow_kinds/lazy_value_func.py

@@ -0,0 +1,194 @@
+import dataclasses
+import functools
+import typing as typ
+from types import MappingProxyType
+
+import jax
+
+from blender_maxwell.utils import extra_sympy_units as spux
+from blender_maxwell.utils import logger
+
+log = logger.get(__name__)
+
+LazyFunction: typ.TypeAlias = typ.Callable[[typ.Any, ...], typ.Any]
+
+
+@dataclasses.dataclass(frozen=True, kw_only=True)
+class LazyValueFuncFlow:
+	r"""Wraps a composable function, providing useful information and operations.
+
+	# Data Flow as Function Composition
+	When using nodes to do math, it can be a good idea to express a **flow of data as the composition of functions**.
+
+	Each node creates a new function, which uses the still-unknown (aka. **lazy**) output of the previous function to plan some calculations.
+	Some new arguments may also be added, of course.
+
+	## Root Function
+	Of course, one needs to select a "bottom" function, which has no previous function as input.
+	Thus, the first step is to define this **root function**:
+
+	$$
+		f_0:\ \ \ \ \biggl(
+			\underbrace{a_1, a_2, ..., a_p}_{\texttt{args}},\ 
+			\underbrace{
+				\begin{bmatrix} k_1 \\ v_1\end{bmatrix},
+				\begin{bmatrix} k_2 \\ v_2\end{bmatrix},
+				...,
+				\begin{bmatrix} k_q \\ v_q\end{bmatrix}
+			}_{\texttt{kwargs}}
+		\biggr) \to \text{output}_0
+	$$
+
+	We'll express this simple snippet like so:
+
+	```python
+	# Presume 'A0', 'KV0' contain only the args/kwargs for f_0
+	## 'A0', 'KV0' are of length 'p' and 'q'
+	def f_0(*args, **kwargs): ...
+
+	lazy_value_func_0 = LazyValueFuncFlow(
+		func=f_0,
+		func_args=[(a_i, type(a_i)) for a_i in A0],
+		func_kwargs={k: v for k,v in KV0},
+	)
+	output_0 = lazy_value_func.func(*A0_computed, **KV0_computed)
+	```
+
+	So far so good.
+	But of course, nothing interesting has really happened yet.
+
+	## Composing Functions
+	The key thing is the next step: The function that uses the result of $f_0$!
+
+	$$
+		f_1:\ \ \ \ \biggl(
+			f_0(...),\ \ 
+			\underbrace{\{a_i\}_p^{p+r}}_{\texttt{args[p:]}},\ 
+			\underbrace{\biggl\{
+				\begin{bmatrix} k_i \\ v_i\end{bmatrix}
+			\biggr\}_q^{q+s}}_{\texttt{kwargs[p:]}}
+		\biggr) \to \text{output}_1
+	$$
+
+	Notice that _$f_1$ needs the arguments of both $f_0$ and $f_1$_.
+	Tracking arguments is already getting out of hand; we already have to use `...` to keep it readeable!
+
+	But doing so with `LazyValueFunc` is not so complex:
+
+	```python
+	# Presume 'A1', 'K1' contain only the args/kwarg names for f_1
+	## 'A1', 'KV1' are therefore of length 'r' and 's'
+	def f_1(output_0, *args, **kwargs): ...
+
+	lazy_value_func_1 = lazy_value_func_0.compose_within(
+		enclosing_func=f_1,
+		enclosing_func_args=[(a_i, type(a_i)) for a_i in A1],
+		enclosing_func_kwargs={k: type(v) for k,v in K1},
+	)
+
+	A_computed = A0_computed + A1_computed
+	KW_computed = KV0_computed + KV1_computed
+	output_1 = lazy_value_func_1.func(*A_computed, **KW_computed)
+	```
+
+	We only need the arguments to $f_1$, and `LazyValueFunc` figures out how to make one function with enough arguments to call both.
+
+	## Isn't Laying Functions Slow/Hard?
+	Imagine that each function represents the action of a node, each of which performs expensive calculations on huge `numpy` arrays (**as one does when processing electromagnetic field data**).
+	At the end, a node might run the entire procedure with all arguments:
+
+	```python
+	output_n = lazy_value_func_n.func(*A_all, **KW_all)
+	```
+	
+	It's rough: Most non-trivial pipelines drown in the time/memory overhead of incremental `numpy` operations - individually fast, but collectively iffy.
+
+	The killer feature of `LazyValueFuncFlow` is a sprinkle of black magic:
+	
+	```python
+	func_n_jax = lazy_value_func_n.func_jax
+	output_n = func_n_jax(*A_all, **KW_all)  ## Runs on your GPU
+	```
+
+	What happened was, **the entire pipeline** was compiled and optimized for high performance on not just your CPU, _but also (possibly) your GPU_.
+	All the layered function calls and inefficient incremental processing is **transformed into a high-performance program**.
+
+	Thank `jax` - specifically, `jax.jit` (https://jax.readthedocs.io/en/latest/_autosummary/jax.jit.html#jax.jit), which internally enables this magic with a single function call.
+	
+	## Other Considerations
+	**Auto-Differentiation**: Incredibly, `jax.jit` isn't the killer feature of `jax`. The function that comes out of `LazyValueFuncFlow` can also be differentiated with `jax.grad` (read: high-performance Jacobians for optimizing input parameters).
+
+	Though designed for machine learning, there's no reason other fields can't enjoy their inventions!
+
+	**Impact of Independent Caching**: JIT'ing can be slow.
+	That's why `LazyValueFuncFlow` has its own `FlowKind` "lane", which means that **only changes to the processing procedures will cause recompilation**.
+
+	Generally, adjustable values that affect the output will flow via the `Param` "lane", which has its own incremental caching, and only meets the compiled function when it's "plugged in" for final evaluation.
+	The effect is a feeling of snappiness and interactivity, even as the volume of data grows.
+
+	Attributes:
+		func: The function that the object encapsulates.
+		bound_args: Arguments that will be packaged into function, which can't be later modifier.
+		func_kwargs: Arguments to be specified by the user at the time of use.
+		supports_jax: Whether the contained `self.function` can be compiled with JAX's JIT compiler.
+	"""
+
+	func: LazyFunction
+	func_args: list[spux.MathType | spux.PhysicalType] = dataclasses.field(
+		default_factory=list
+	)
+	func_kwargs: dict[str, spux.MathType | spux.PhysicalType] = dataclasses.field(
+		default_factory=dict
+	)
+	supports_jax: bool = False
+
+	# Merging
+	def __or__(
+		self,
+		other: typ.Self,
+	):
+		return LazyValueFuncFlow(
+			func=lambda *args, **kwargs: (
+				self.func(
+					*list(args[: len(self.func_args)]),
+					**{k: v for k, v in kwargs.items() if k in self.func_kwargs},
+				),
+				other.func(
+					*list(args[len(self.func_args) :]),
+					**{k: v for k, v in kwargs.items() if k in other.func_kwargs},
+				),
+			),
+			func_args=self.func_args + other.func_args,
+			func_kwargs=self.func_kwargs | other.func_kwargs,
+			supports_jax=self.supports_jax and other.supports_jax,
+		)
+
+	# Composition
+	def compose_within(
+		self,
+		enclosing_func: LazyFunction,
+		enclosing_func_args: list[type] = (),
+		enclosing_func_kwargs: dict[str, type] = MappingProxyType({}),
+		supports_jax: bool = False,
+	) -> typ.Self:
+		return LazyValueFuncFlow(
+			func=lambda *args, **kwargs: enclosing_func(
+				self.func(
+					*list(args[: len(self.func_args)]),
+					**{k: v for k, v in kwargs.items() if k in self.func_kwargs},
+				),
+				*args[len(self.func_args) :],
+				**{k: v for k, v in kwargs.items() if k not in self.func_kwargs},
+			),
+			func_args=self.func_args + list(enclosing_func_args),
+			func_kwargs=self.func_kwargs | dict(enclosing_func_kwargs),
+			supports_jax=self.supports_jax and supports_jax,
+		)
+
+	@functools.cached_property
+	def func_jax(self) -> LazyFunction:
+		if self.supports_jax:
+			return jax.jit(self.func)
+
+		msg = 'Can\'t express LazyValueFuncFlow as JAX function (using jax.jit), since "self.supports_jax" is False'
+		raise ValueError(msg)

src/blender_maxwell/node_trees/maxwell_sim_nodes/contracts/flow_kinds/params.py

@@ -0,0 +1,95 @@
+import dataclasses
+import functools
+import typing as typ
+from types import MappingProxyType
+
+import sympy as sp
+
+from blender_maxwell.utils import extra_sympy_units as spux
+from blender_maxwell.utils import logger
+
+log = logger.get(__name__)
+
+
+@dataclasses.dataclass(frozen=True, kw_only=True)
+class ParamsFlow:
+	func_args: list[spux.SympyExpr] = dataclasses.field(default_factory=list)
+	func_kwargs: dict[str, spux.SympyExpr] = dataclasses.field(default_factory=dict)
+
+	symbols: frozenset[spux.Symbol] = frozenset()
+
+	@functools.cached_property
+	def sorted_symbols(self) -> list[sp.Symbol]:
+		"""Retrieves all symbols by concatenating int, real, and complex symbols, and sorting them by name.
+
+		Returns:
+			All symbols valid for use in the expression.
+		"""
+		return sorted(self.symbols, key=lambda sym: sym.name)
+
+	####################
+	# - Scaled Func Args
+	####################
+	def scaled_func_args(
+		self,
+		unit_system: spux.UnitSystem,
+		symbol_values: dict[spux.Symbol, spux.SympyExpr] = MappingProxyType({}),
+	):
+		"""Return the function arguments, scaled to the unit system, stripped of units, and cast to jax-compatible arguments."""
+		if not all(sym in self.symbols for sym in symbol_values):
+			msg = f"Symbols in {symbol_values} don't perfectly match the ParamsFlow symbols {self.symbols}"
+			raise ValueError(msg)
+
+		return [
+			spux.scale_to_unit_system(arg, unit_system, use_jax_array=True)
+			if arg not in symbol_values
+			else symbol_values[arg]
+			for arg in self.func_args
+		]
+
+	def scaled_func_kwargs(
+		self,
+		unit_system: spux.UnitSystem,
+		symbol_values: dict[spux.Symbol, spux.SympyExpr] = MappingProxyType({}),
+	):
+		"""Return the function arguments, scaled to the unit system, stripped of units, and cast to jax-compatible arguments."""
+		if not all(sym in self.symbols for sym in symbol_values):
+			msg = f"Symbols in {symbol_values} don't perfectly match the ParamsFlow symbols {self.symbols}"
+			raise ValueError(msg)
+
+		return {
+			arg_name: spux.convert_to_unit_system(arg, unit_system, use_jax_array=True)
+			if arg not in symbol_values
+			else symbol_values[arg]
+			for arg_name, arg in self.func_kwargs.items()
+		}
+
+	####################
+	# - Operations
+	####################
+	def __or__(
+		self,
+		other: typ.Self,
+	):
+		"""Combine two function parameter lists, such that the LHS will be concatenated with the RHS.
+
+		Just like its neighbor in `LazyValueFunc`, this effectively combines two functions with unique parameters.
+		The next composed function will receive a tuple of two arrays, instead of just one, allowing binary operations to occur.
+		"""
+		return ParamsFlow(
+			func_args=self.func_args + other.func_args,
+			func_kwargs=self.func_kwargs | other.func_kwargs,
+			symbols=self.symbols | other.symbols,
+		)
+
+	def compose_within(
+		self,
+		enclosing_func_args: list[spux.SympyExpr] = (),
+		enclosing_func_kwargs: dict[str, spux.SympyExpr] = MappingProxyType({}),
+		enclosing_symbols: frozenset[spux.Symbol] = frozenset(),
+	) -> typ.Self:
+		return ParamsFlow(
+			func_args=self.func_args + list(enclosing_func_args),
+			func_kwargs=self.func_kwargs | dict(enclosing_func_kwargs),
+			symbols=self.symbols | enclosing_symbols,
+		)

src/blender_maxwell/node_trees/maxwell_sim_nodes/contracts/flow_kinds/value.py

@@ -0,0 +1,3 @@
+import typing as typ
+
+ValueFlow: typ.TypeAlias = typ.Any

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/monitors/field_power_flux_monitor.py

@@ -116,7 +116,7 @@ class PowerFluxMonitorNode(base.MaxwellSimNode):
 			size=input_sockets['Size'],
 			name=props['sim_node_name'],
 			interval_space=(1, 1, 1),
-			freqs=input_sockets['Freqs'].realize().values,
+			freqs=input_sockets['Freqs'].realize_array,
 			normal_dir='+' if input_sockets['Direction'] else '-',
 		)
 
@@ -142,11 +142,11 @@ class PowerFluxMonitorNode(base.MaxwellSimNode):
 
 	@events.on_value_changed(
 		# Trigger
-		socket_name={'Center', 'Size'},
+		socket_name={'Center', 'Size', 'Direction'},
 		run_on_init=True,
 		# Loaded
 		managed_objs={'mesh', 'modifier'},
-		input_sockets={'Center', 'Size'},
+		input_sockets={'Center', 'Size', 'Direction'},
 		unit_systems={'BlenderUnits': ct.UNITS_BLENDER},
 		scale_input_sockets={
 			'Center': 'BlenderUnits',
@@ -167,6 +167,7 @@ class PowerFluxMonitorNode(base.MaxwellSimNode):
 				'unit_system': unit_systems['BlenderUnits'],
 				'inputs': {
 					'Size': input_sockets['Size'],
+					'Direction': input_sockets['Direction'],
 				},
 			},
 		)

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/outputs/web_exporters/tidy3d_web_exporter.py

@@ -320,7 +320,7 @@ class Tidy3DWebExporterNode(base.MaxwellSimNode):
 	def on_sim_changed(self, props) -> None:
 		# Sim Linked | First Value Change
 		if self.inputs['Sim'].is_linked and not props['sim_info_available']:
-			log.critical('First Change: Mark Sim Info Available')
+			log.debug('%s: First Change; Mark Sim Info Available', self.sim_node_name)
 			self.sim = bl_cache.Signal.InvalidateCache
 			self.total_monitor_data = bl_cache.Signal.InvalidateCache
 			self.is_sim_uploadable = bl_cache.Signal.InvalidateCache
@@ -332,7 +332,7 @@ class Tidy3DWebExporterNode(base.MaxwellSimNode):
 			and props['sim_info_available']
 			and not props['sim_info_invalidated']
 		):
-			log.critical('Second Change: Mark Sim Info Invalided')
+			log.debug('%s: Second Change; Mark Sim Info Invalided', self.sim_node_name)
 			self.sim_info_invalidated = True
 
 		# Sim Linked | Nth Time
@@ -346,7 +346,9 @@ class Tidy3DWebExporterNode(base.MaxwellSimNode):
 		## -> Luckily, since we know there's no sim, invalidation is cheap.
 		## -> Ends up being a "circuit breaker" for sim_info_invalidated.
 		elif not self.inputs['Sim'].is_linked:
-			log.critical('Unlinked: Short Circuit Zap Cache')
+			log.debug(
+				'%s: Unlinked; Short Circuit the Sim Info Cache', self.sim_node_name
+			)
 			self.sim = bl_cache.Signal.InvalidateCache
 			self.total_monitor_data = bl_cache.Signal.InvalidateCache
 			self.is_sim_uploadable = bl_cache.Signal.InvalidateCache
@@ -368,7 +370,7 @@ class Tidy3DWebExporterNode(base.MaxwellSimNode):
 		props={'uploaded_task_id'},
 	)
 	def on_uploaded_task_changed(self, props):
-		log.critical('Uploaded Task Changed')
+		log.debug('Uploaded Task Changed')
 		self.is_sim_uploadable = bl_cache.Signal.InvalidateCache
 
 		if props['uploaded_task_id'] != '':

src/blender_maxwell/services/tdcloud.py

@@ -49,15 +49,19 @@ def set_offline():
 
 def check_online() -> bool:
 	global IS_ONLINE  # noqa: PLW0603
+	log.info('Checking Internet Connection...')
+
 	try:
 		urllib.request.urlopen(
 			'https://docs.flexcompute.com/projects/tidy3d/en/latest/index.html',
 			timeout=2,
 		)
-	except:
+	except:  # noqa: E722
+		log.info('Internet is currently offline')
 		IS_ONLINE = False
 		return False
 	else:
+		log.info('Internet connection is working')
 		IS_ONLINE = True
 		return True
 
@@ -67,26 +71,25 @@ def check_online() -> bool:
 ####################
 def check_authentication() -> bool:
 	global IS_AUTHENTICATED  # noqa: PLW0603
-	log.critical('Checking Authentication')
-
-	# Check Previous Authentication
-	## If we authenticated once, we presume that it'll work again.
-	## TODO: API keys can change... It would just look like "offline" for now.
-	if IS_AUTHENTICATED:
-		return True
+	log.info('Checking Tidy3D Authentication...')
 
 	api_key = td_web.core.http_util.api_key()
 	if api_key is not None:
+		log.info('Found stored Tidy3D API key')
 		try:
 			td_web.test()
-			set_online()
 		except td.exceptions.WebError:
 			set_offline()
+			log.info('Authenticated to Tidy3D cloud')
 			return False
+		else:
+			set_online()
+			log.info('Authenticated to Tidy3D cloud')
 
 		IS_AUTHENTICATED = True
 		return True
 
+	log.info('Tidy3D API key is missing')
 	return False
 
 
@@ -99,6 +102,7 @@ TD_CONFIG = Path(td_web.cli.constants.CONFIG_FILE)
 
 ## TODO: Robustness is key - internet might be down.
 ## -> I'm not a huge fan of the max 2sec startup time burden
+## -> I also don't love "calling" Tidy3D on startup, privacy-wise
 if TD_CONFIG.is_file() and check_online():
 	check_authentication()
 

src/scripts/dev.py

@@ -83,7 +83,6 @@ if __name__ == '__main__':
 
 	# Run Addon
 	print(f'Blender: Running "{info.ADDON_NAME}"...')
-	subprocess.run
 	return_code, output = run_blender(
 		None, headless=False, load_devfile=True, monitor=True
 	)