Documentation and code updates clarifying the behavior of the in_memory flag

changes/8851.outlier_detection.rst

@@ -0,0 +1 @@
+Update documentation to clarify the interaction between pipeline-level and step-level `--in_memory` flags.

docs/jwst/outlier_detection/arguments.rst

@@ -89,6 +89,8 @@ that control the behavior of the processing:
   Specifies whether or not to load and create all images that are used during
   processing into memory. If ``False``, input files are loaded from disk when
   needed and all intermediate files are stored on disk, rather than in memory.
+  This flag is superseded by the pipeline-level ``--in-memory`` flag, and thus
+  has no effect when running the full level 3 pipeline.
 
 Step Arguments for IFU data
 ===========================

docs/jwst/outlier_detection/outlier_detection_imaging.rst

@@ -171,6 +171,10 @@ during processing includes:
    Those sections are then read in one at a time to compute the median image.
 
 These changes result in a minimum amount of memory usage during processing at the obvious
-expense of reading and writing the products from disk.
+expense of reading and writing the products from disk. Note that if a ModelLibrary object
+is input to the step, the memory behavior of the step is read from the ``on_disk`` status
+of the ModelLibrary object, and the ``in_memory`` parameter of the step is ignored.
+When running ``calwebb_image3``, the ``in_memory`` flag should therefore be set at the pipeline level,
+e.g., ``strun calwebb_image3 asn.json --in-memory=True``; the step-specific flag will be ignored.
 
 .. automodapi:: jwst.outlier_detection.imaging

jwst/outlier_detection/imaging.py

@@ -65,7 +65,6 @@ def detect_outliers(
             kernel=kernel,
             fillval=fillval,
             good_bits=good_bits,
-            in_memory=in_memory,
             allowed_memory=allowed_memory,
         )
         median_data, median_wcs = median_with_resampling(input_models,

jwst/outlier_detection/outlier_detection_step.py

@@ -67,7 +67,7 @@ class OutlierDetectionStep(Step):
         good_bits = string(default="~DO_NOT_USE")  # DQ flags to allow
         search_output_file = boolean(default=False)
         allowed_memory = float(default=None)  # Fraction of memory to use for the combined image
-        in_memory = boolean(default=False)
+        in_memory = boolean(default=False) # ignored if run within the pipeline; set at pipeline level instead
     """
 
     def process(self, input_data):

jwst/outlier_detection/spec.py

@@ -66,7 +66,6 @@ def detect_outliers(
             kernel=kernel,
             fillval=fillval,
             good_bits=good_bits,
-            in_memory=in_memory,
         )
 
         median_data, median_wcs = median_with_resampling(