feat: Implemented fit of experim. medium data.

It's only good for dispersive media; specifically, a text file with
three floats per line: 'wl n k'.
A custom script was used to convert Maxim's data.

It's very fast, and has a ton of options.
Only the most important are exposed in the node for now.

A bug in MPL plotting aspect ratio declaration on MPL axis object was
fixed by manually running `set_aspect('auto')` after the fact.
It shouldn't do anything, and it doesn't, other than fix the bug :)

Also brought the plotting function of the viewer to parity with
the 3D preview, so the "Auto Plot" button works as expected.

TODO.md

@@ -1,5 +1,5 @@
 # Acute Tasks
-- Implement Material Import for Maxim Data
+- [x] Implement Material Import for Maxim Data
 - Move preview GN trees to the asset library.
 
 

src/blender_maxwell/node_trees/maxwell_sim_nodes/managed_objs/managed_bl_image.py

@@ -6,8 +6,11 @@ import matplotlib.axis as mpl_ax
 import numpy as np
 import typing_extensions as typx
 
+from ....utils import logger
 from .. import contracts as ct
 
+log = logger.get(__name__)
+
 AREA_TYPE = 'IMAGE_EDITOR'
 SPACE_TYPE = 'IMAGE_EDITOR'
 
@@ -163,6 +166,7 @@ class ManagedBLImage(ct.schemas.ManagedObj):
 		# Compute Plot Dimensions
 		aspect_ratio = _width_inches / _height_inches
 
+		log.debug('Create MPL Axes (aspect=%d, width=%d, height=%d)', aspect_ratio, _width_inches, _height_inches)
 		# Create MPL Figure, Axes, and Compute Figure Geometry
 		fig, ax = plt.subplots(
 			figsize=[_width_inches, _height_inches],
@@ -171,6 +175,7 @@ class ManagedBLImage(ct.schemas.ManagedObj):
 		ax.set_aspect(aspect_ratio)
 		cmp_width_px, cmp_height_px = fig.canvas.get_width_height()
 		## Use computed pixel w/h to preempt off-by-one size errors.
+		ax.set_aspect('auto')  ## Workaround aspect-ratio bugs
 
 		# Plot w/User Parameter
 		func_plotter(ax)

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/inputs/file_importers/tidy_3d_file_importer.py

@@ -3,21 +3,39 @@ from pathlib import Path
 
 import bpy
 import tidy3d as td
+import tidy3d.plugins.dispersion as td_dispersion
 
 from ......utils import logger
 from .... import contracts as ct
-from .... import sockets
+from .... import managed_objs, sockets
 from ... import base, events
 
 log = logger.get(__name__)
 
-TD_FILE_EXTS = {
+VALID_FILE_EXTS = {
+	'SIMULATION_DATA': {
+		'.hdf5.gz',
+		'.hdf5',
+	},
+	'SIMULATION': {
 		'.hdf5.gz',
 		'.hdf5',
 		'.json',
 		'.yaml',
+	},
+	'MEDIUM': {
+		'.hdf5.gz',
+		'.hdf5',
+		'.json',
+		'.yaml',
+	},
+	'EXPERIM_DISP_MEDIUM': {
+		'.txt',
+	},
 }
 
+CACHE = {}
+
 
 ####################
 # - Node
@@ -29,25 +47,69 @@ class Tidy3DFileImporterNode(base.MaxwellSimNode):
 	input_sockets: typ.ClassVar = {
 		'File Path': sockets.FilePathSocketDef(),
 	}
+	managed_obj_defs: typ.ClassVar = {
+		'plot': ct.schemas.ManagedObjDef(
+			mk=lambda name: managed_objs.ManagedBLImage(name),
+			name_prefix='',
+		),
+	}
 
+	####################
+	# - Properties
+	####################
 	tidy3d_type: bpy.props.EnumProperty(
 		name='Tidy3D Type',
 		description='Type of Tidy3D object to load',
 		items=[
 			(
 				'SIMULATION_DATA',
-				'Simulation Data',
+				'Sim Data',
 				'Data from Completed Tidy3D Simulation',
 			),
-			('SIMULATION', 'Simulation', 'Tidy3D Simulation'),
+			('SIMULATION', 'Sim', 'Tidy3D Simulation'),
 			('MEDIUM', 'Medium', 'A Tidy3D Medium'),
+			(
+				'EXPERIM_DISP_MEDIUM',
+				'Experim Disp Medium',
+				'A pole-residue fit of experimental dispersive medium data, described by a .txt file specifying wl, n, k',
+			),
 		],
 		default='SIMULATION_DATA',
 		update=lambda self, context: self.sync_prop('tidy3d_type', context),
 	)
 
+	disp_fit__min_poles: bpy.props.IntProperty(
+		name='min Poles',
+		description='Min. # poles to fit to the experimental dispersive medium data',
+		default=1,
+	)
+	disp_fit__max_poles: bpy.props.IntProperty(
+		name='max Poles',
+		description='Max. # poles to fit to the experimental dispersive medium data',
+		default=5,
+	)
+	## TODO: Bool of whether to fit eps_inf, with conditional choice of eps_inf as socket
+	disp_fit__tolerance_rms: bpy.props.FloatProperty(
+		name='Max RMS',
+		description='The RMS error threshold, below which the fit should be considered converged',
+		default=0.001,
+		precision=5,
+	)
+	## TODO: "AdvanceFastFitterParam" options incl. loss_bounds, weights, show_progress, show_unweighted_rms, relaxed, smooth, logspacing, numiters, passivity_num_iters, and slsqp_constraint_scale
+
+	def draw_props(self, _: bpy.types.Context, col: bpy.types.UILayout):
+		col.prop(self, 'tidy3d_type', text='')
+		if self.tidy3d_type == 'EXPERIM_DISP_MEDIUM':
+			row = col.row(align=True)
+			row.alignment = 'CENTER'
+			row.label(text='Pole-Residue Fit')
+
+			col.prop(self, 'disp_fit__min_poles')
+			col.prop(self, 'disp_fit__max_poles')
+			col.prop(self, 'disp_fit__tolerance_rms')
+
 	####################
-	# - Event Methods: Compute Output Data
+	# - Event Methods: Output Data
 	####################
 	def _compute_sim_data_for(
 		self, output_socket_name: str, file_path: Path
@@ -79,6 +141,39 @@ class Tidy3DFileImporterNode(base.MaxwellSimNode):
 	def compute_medium(self, input_sockets: dict) -> td.Medium:
 		return self._compute_sim_data_for('Medium', input_sockets['File Path'])
 
+	####################
+	# - Event Methods: Output Data | Dispersive Media
+	####################
+	@events.computes_output_socket(
+		'Experim Disp Medium',
+		input_sockets={'File Path'},
+	)
+	def compute_experim_disp_medium(self, input_sockets: dict) -> td.Medium:
+		if CACHE.get(self.bl_label) is not None:
+			log.debug('Reusing Cached Dispersive Medium')
+			return CACHE[self.bl_label]['model']
+
+		log.info('Loading Experimental Data')
+		dispersion_fitter = td_dispersion.FastDispersionFitter.from_file(
+			str(input_sockets['File Path'])
+		)
+
+		log.info('Computing Fast Dispersive Fit of Experimental Data...')
+		pole_residue_medium, rms_error = dispersion_fitter.fit(
+			min_num_poles=self.disp_fit__min_poles,
+			max_num_poles=self.disp_fit__max_poles,
+			tolerance_rms=self.disp_fit__tolerance_rms,
+		)
+		log.info('Fit Succeeded w/RMS "%s"!', f'{rms_error:.5f}')
+
+		# Populate Cache
+		CACHE[self.bl_label] = {}
+		CACHE[self.bl_label]['model'] = pole_residue_medium
+		CACHE[self.bl_label]['fitter'] = dispersion_fitter
+		CACHE[self.bl_label]['rms_error'] = rms_error
+
+		return pole_residue_medium
+
 	####################
 	# - Event Methods: Setup Output Socket
 	####################
@@ -89,8 +184,14 @@ class Tidy3DFileImporterNode(base.MaxwellSimNode):
 		props={'tidy3d_type'},
 	)
 	def on_file_changed(self, input_sockets: dict, props: dict):
+		if CACHE.get(self.bl_label) is not None:
+			del CACHE[self.bl_label]
+
 		file_ext = ''.join(input_sockets['File Path'].suffixes)
-		if not (input_sockets['File Path'].is_file() and file_ext in TD_FILE_EXTS):
+		if not (
+			input_sockets['File Path'].is_file()
+			and file_ext in VALID_FILE_EXTS[props['tidy3d_type']]
+		):
 			self.loose_output_sockets = {}
 		else:
 			self.loose_output_sockets = {
@@ -99,8 +200,43 @@ class Tidy3DFileImporterNode(base.MaxwellSimNode):
 				},
 				'SIMULATION': {'Sim': sockets.MaxwellFDTDSimDataSocketDef()},
 				'MEDIUM': {'Medium': sockets.MaxwellMediumSocketDef()},
+				'EXPERIM_DISP_MEDIUM': {
+					'Experim Disp Medium': sockets.MaxwellMediumSocketDef()
+				},
 			}[props['tidy3d_type']]
 
+	####################
+	# - Event Methods: Plot
+	####################
+	@events.on_show_plot(
+		managed_objs={'plot'},
+		props={'tidy3d_type'},
+	)
+	def on_show_plot(
+		self,
+		props: dict,
+		managed_objs: dict,
+	):
+		"""When the filetype is 'Experimental Dispersive Medium', plot the computed model against the input data."""
+		if props['tidy3d_type'] == 'EXPERIM_DISP_MEDIUM':
+			# Populate Cache
+			if CACHE.get(self.bl_label) is None:
+				model_medium = self.compute_experim_disp_medium()
+				disp_fitter = CACHE[self.bl_label]['fitter']
+			else:
+				model_medium = CACHE[self.bl_label]['model']
+				disp_fitter = CACHE[self.bl_label]['fitter']
+
+			# Plot
+			log.debug(disp_fitter)
+			managed_objs['plot'].mpl_plot_to_image(
+				lambda ax: disp_fitter.plot(
+					medium=model_medium,
+					ax=ax,
+				),
+				bl_select=True,
+			)
+
 
 ####################
 # - Blender Registration

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/outputs/viewer.py

@@ -23,7 +23,6 @@ class ConsoleViewOperator(bpy.types.Operator):
 
 	def execute(self, context):
 		node = context.node
-		print('Executing Operator')
 
 		node.print_data_to_console()
 		return {'FINISHED'}
@@ -39,7 +38,7 @@ class RefreshPlotViewOperator(bpy.types.Operator):
 
 	def execute(self, context):
 		node = context.node
-		node.trigger_action('value_changed', 'Data')
+		node.on_changed_plot_preview()
 		return {'FINISHED'}
 
 
@@ -67,7 +66,7 @@ class ViewerNode(base.MaxwellSimNode):
 	auto_3d_preview: bpy.props.BoolProperty(
 		name='Auto 3D Preview',
 		description="Whether to auto-preview anything 3D, that's plugged into the viewer node",
-		default=False,
+		default=True,
 		update=lambda self, context: self.sync_prop('auto_3d_preview', context),
 	)
 
@@ -126,18 +125,14 @@ class ViewerNode(base.MaxwellSimNode):
 	# - Event Methods
 	####################
 	@events.on_value_changed(
-		socket_name='Data',
+		prop_name='auto_plot',
 		props={'auto_plot'},
 	)
-	def on_changed_2d_data(self, props):
+	def on_changed_plot_preview(self, props):
-		# Show Plot
-		## Don't have to un-show other plots.
 		if self.inputs['Data'].is_linked and props['auto_plot']:
+			log.info('Enabling 2D Plot from "%s"', self.name)
 			self.trigger_action('show_plot')
 
-	####################
-	# - Event Methods: 3D Preview
-	####################
 	@events.on_value_changed(
 		prop_name='auto_3d_preview',
 		props={'auto_3d_preview'},
@@ -159,6 +154,7 @@ class ViewerNode(base.MaxwellSimNode):
 		# Just Linked / Just Unlinked: Preview/Unpreview
 		if self.inputs['Data'].is_linked ^ self.cache__data_socket_linked:
 			self.on_changed_3d_preview()
+			self.on_changed_plot_preview()
 			self.cache__data_socket_linked = self.inputs['Data'].is_linked