Adds "repeat_layers" option to contrasts

Author: DrPaulSharp

ratapi/inputs.py

@@ -302,7 +302,7 @@ def make_problem(project: ratapi.Project) -> ProblemDefinition:
     problem.numberOfContrasts = len(project.contrasts)
     problem.geometry = project.geometry
     problem.useImaginary = project.absorption
-    problem.repeatLayers = [1] * len(project.contrasts)
+    problem.repeatLayers = [contrast.repeat_layers for contrast in project.contrasts]
     problem.contrastBackgroundParams = contrast_background_params
     problem.contrastBackgroundTypes = contrast_background_types
     problem.contrastBackgroundActions = [contrast.background_action for contrast in project.contrasts]

ratapi/models.py

@@ -163,6 +163,8 @@ class Contrast(RATModel):
         The name of the instrument resolution for this contrast.
     resample : bool
         Whether adaptive resampling should be used for interface microslicing.
+    repeat_layers : int
+        For standard layers, the number of times the set of layers defined in the model should be repeated.
     model : list[str]
         If this is a standard layers model, this should be a list of layer names
         that make up the slab model for this contrast.
@@ -180,6 +182,7 @@ class Contrast(RATModel):
     scalefactor: str = ""
     resolution: str = ""
     resample: bool = False
+    repeat_layers: int = Field(default=1, gt=0)
     model: list[str] = []
 
     @model_validator(mode="before")
@@ -208,6 +211,7 @@ def __str__(self):
                 self.scalefactor,
                 self.resolution,
                 self.resample,
+                self.repeat_layers,
                 model_entry,
             ]
         )
@@ -238,6 +242,8 @@ class ContrastWithRatio(RATModel):
         The name of the instrument resolution for this contrast.
     resample : bool
         Whether adaptive resampling should be used for interface microslicing.
+    repeat_layers : int
+        For standard layers, the number of times the set of layers defined in the model should be repeated.
     domain_ratio : str
         The name of the domain ratio parameter describing how the first domain should be weighted
         relative to the second.
@@ -258,6 +264,7 @@ class ContrastWithRatio(RATModel):
     scalefactor: str = ""
     resolution: str = ""
     resample: bool = False
+    repeat_layers: int = Field(default=1, gt=0)
     domain_ratio: str = ""
     model: list[str] = []
 
@@ -276,6 +283,8 @@ def __str__(self):
                 self.scalefactor,
                 self.resolution,
                 self.resample,
+                self.repeat_layers,
+                self.domain_ratio,
                 model_entry,
             ]
         )

ratapi/project.py

@@ -454,6 +454,20 @@ def set_layers(self) -> "Project":
             self.layers.data = []
         return self
 
+    @model_validator(mode="after")
+    def set_repeat_layers(self) -> "Project":
+        """If we are not using a standard layers model, warn that the repeat layers setting is not valid."""
+        if self.model != LayerModels.StandardLayers:
+            for contrast in self.contrasts:
+                if "repeat_layers" in contrast.model_fields_set and contrast.repeat_layers != 1:
+                    warnings.warn(
+                        'For a custom layers or custom XY calculation, the "repeat_layers" setting for each '
+                        "contrast is not valid - resetting to 1.",
+                        stacklevel=2,
+                    )
+                contrast.repeat_layers = 1
+        return self
+
     @model_validator(mode="after")
     def set_resample(self) -> "Project":
         """If we are using a custom XY model, warn that the resample setting for each contrast must always be True."""

tests/test_project.py

@@ -443,6 +443,29 @@ def test_set_layers(project_parameters: dict) -> None:
     assert project.layers == []
 
 
+@pytest.mark.parametrize(
+    "project_parameters",
+    [
+        (
+            {
+                "model": LayerModels.CustomLayers,
+                "contrasts": [ratapi.models.Contrast(name="Test Contrast", repeat_layers=2)],
+            }
+        ),
+        ({"model": LayerModels.CustomXY, "contrasts": [ratapi.models.Contrast(name="Test Contrast", repeat_layers=2)]}),
+    ],
+)
+def test_set_repeat_layers(project_parameters: dict) -> None:
+    """If we are using a custom layers of custom XY model, the "resample" field of all the contrasts should always
+    be 1."""
+    with pytest.warns(
+        match='For a custom layers or custom XY calculation, the "repeat_layers" setting for each '
+        "contrast is not valid - resetting to 1."
+    ):
+        project = ratapi.Project(**project_parameters)
+    assert all(contrast.repeat_layers == 1 for contrast in project.contrasts)
+
+
 @pytest.mark.parametrize(
     "project_parameters",
     [