Cache expensive @Property on Fit classes as @cached_property

FitDataset, FitImaging, and FitInterferometer properties like
model_data, residual_map, chi_squared_map, and log_likelihood were
recomputing on every access despite depending only on immutable
constructor args. For Delaunay inversions model_data alone cost
5-20s — downstream properties accessed it redundantly, creating
a cascade of recomputation.

Changed @Property to @functools.cached_property. Safe because Fit
objects are constructed once and never mutated, and none of these
classes use __getstate__ or JAX pytree registration on the Fit
object itself.

Closes PyAutoArray#340

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: 2 people

autolens/imaging/fit_imaging.py

@@ -19,6 +19,7 @@
 The ``TracerToInversion`` helper is used to assemble the linear system in step 4.
 """
 import copy
+import functools
 import numpy as np
 from typing import Dict, List, Optional
 
@@ -94,7 +95,7 @@ def __init__(
         self.adapt_images = adapt_images
         self.settings = settings or aa.Settings()
 
-    @property
+    @functools.cached_property
     def blurred_image(self) -> aa.Array2D:
         """
         Returns the image of all light profiles in the fit's tracer convolved with the imaging dataset's PSF.
@@ -115,7 +116,7 @@ def blurred_image(self) -> aa.Array2D:
             xp=self._xp,
         )
 
-    @property
+    @functools.cached_property
     def profile_subtracted_image(self) -> aa.Array2D:
         """
         Returns the dataset's image with all blurred light profile images in the fit's tracer subtracted.
@@ -155,7 +156,7 @@ def inversion(self) -> Optional[aa.AbstractInversion]:
 
             return self.tracer_to_inversion.inversion
 
-    @property
+    @functools.cached_property
     def model_data(self) -> aa.Array2D:
         """
         Returns the model-image that is used to fit the data.
@@ -226,7 +227,7 @@ def galaxy_model_image_dict(self) -> Dict[ag.Galaxy, np.ndarray]:
 
         return {**galaxy_blurred_image_2d_dict, **galaxy_linear_obj_image_dict}
 
-    @property
+    @functools.cached_property
     def subtracted_images_of_galaxies_dict(self) -> Dict[ag.Galaxy, np.ndarray]:
         """
         A dictionary which associates every galaxy in the tracer with its `subtracted image`.
@@ -249,7 +250,7 @@ def subtracted_images_of_galaxies_dict(self) -> Dict[ag.Galaxy, np.ndarray]:
 
         return subtracted_images_of_galaxies_dict
 
-    @property
+    @functools.cached_property
     def subtracted_signal_to_noise_maps_of_galaxies_dict(self) -> Dict[ag.Galaxy, np.ndarray]:
         """
         A dictionary which associates every galaxy in the tracer with its `subtracted image`.
@@ -299,7 +300,7 @@ def model_images_of_planes_list(self) -> List[aa.Array2D]:
 
         return model_images_of_planes_list
 
-    @property
+    @functools.cached_property
     def subtracted_images_of_planes_list(self) -> List[aa.Array2D]:
         """
         A list of the subtracted image of every plane.