feat: add sample rotation

Author: jokasimr

src/ess/amor/__init__.py

@@ -14,6 +14,7 @@
     NeXusDetectorName,
     RunType,
     SamplePosition,
+    SampleRotationOffset,
 )
 from . import (
     conversions,
@@ -71,6 +72,7 @@ def default_parameters() -> dict:
             sc.scalar(0.75, unit='deg'),
         ),
         GravityToggle: True,
+        SampleRotationOffset[RunType]: sc.scalar(0.0, unit='deg'),
     }
 
 

src/ess/amor/load.py

@@ -11,6 +11,7 @@
     NeXusDetectorName,
     ProtonCurrent,
     RawDetectorData,
+    RawSampleRotation,
     RunType,
     SampleRotation,
     SampleSize,
@@ -100,7 +101,7 @@ def load_amor_ch_frequency(ch: RawChopper[RunType]) -> ChopperFrequency[RunType]
     raise ValueError("No unit was found for the chopper frequency")
 
 
-def load_amor_sample_rotation(fp: Filename[RunType]) -> SampleRotation[RunType]:
+def load_amor_sample_rotation(fp: Filename[RunType]) -> RawSampleRotation[RunType]:
     (mu,) = load_nx(fp, "NXentry/NXinstrument/master_parameters/mu")
     # Jochens Amor code reads the first value of this log
     # see https://github.com/jochenstahn/amor/blob/140e3192ddb7e7f28acee87e2acaee65ce1332aa/libeos/file_reader.py#L272  # noqa: E501

src/ess/estia/__init__.py

@@ -14,6 +14,7 @@
     NeXusDetectorName,
     RunType,
     SamplePosition,
+    SampleRotationOffset,
 )
 from . import conversions, load, maskings, normalization, orso, resolution, workflow
 from .types import (
@@ -57,6 +58,7 @@ def default_parameters() -> dict:
             sc.scalar(-0.75, unit='deg'),
             sc.scalar(0.75, unit='deg'),
         ),
+        SampleRotationOffset[RunType]: sc.scalar(0.0, unit='deg'),
     }
 
 

src/ess/estia/load.py

@@ -6,12 +6,14 @@
     Filename,
     RawDetectorData,
     RunType,
+    SampleRotationOffset,
 )
 from .mcstas import parse_events_ascii, parse_events_h5
 
 
 def load_mcstas_events(
     filename: Filename[RunType],
+    sample_rotation_offset: SampleRotationOffset[RunType],
 ) -> RawDetectorData[RunType]:
     """
     Load event data from a McStas run and reshape it
@@ -31,6 +33,9 @@ def load_mcstas_events(
     da.coords['detector_rotation'] = 2 * da.coords['sample_rotation'] + sc.scalar(
         1.65, unit='deg'
     )
+    da.coords['sample_rotation'] += sample_rotation_offset.to(
+        unit=da.coords['sample_rotation'].unit
+    )
 
     xbins = sc.linspace('x', -0.25, 0.25, 14 * 32 + 1)
     ybins = sc.linspace('y', -0.25, 0.25, 65)

src/ess/reflectometry/__init__.py

@@ -10,10 +10,11 @@
     __version__ = "0.0.0"
 
 
-from . import conversions, figures, normalization, orso
+from . import conversions, corrections, figures, normalization, orso
 from .load import load_reference, save_reference
 
 providers = (
+    *corrections.providers,
     *conversions.providers,
     *orso.providers,
     *normalization.providers,

src/ess/reflectometry/corrections.py

@@ -2,6 +2,7 @@
 import scipp as sc
 
 from .tools import fwhm_to_std
+from .types import RawSampleRotation, RunType, SampleRotation, SampleRotationOffset
 
 
 def footprint_on_sample(
@@ -45,3 +46,12 @@ def correct_by_footprint(da: sc.DataArray) -> sc.DataArray:
 def correct_by_proton_current(da: sc.DataArray) -> sc.DataArray:
     "Corrects the data by the proton current during the time of data collection"
     return da / da.bins.coords['proton_current']
+
+
+def correct_sample_rotation(
+    mu: RawSampleRotation[RunType], mu_offset: SampleRotationOffset[RunType]
+) -> SampleRotation[RunType]:
+    return mu + mu_offset.to(unit=mu.unit)
+
+
+providers = (correct_sample_rotation,)

src/ess/reflectometry/types.py

@@ -79,10 +79,19 @@ class Filename(sciline.Scope[RunType, str], str):
     """Filename of an event data nexus file."""
 
 
+class RawSampleRotation(sciline.Scope[RunType, sc.Variable], sc.Variable):
+    """The rotation of the sample registered in the NeXus file."""
+
+
 class SampleRotation(sciline.Scope[RunType, sc.Variable], sc.Variable):
     """The rotation of the sample relative to the center of the incoming beam."""
 
 
+class SampleRotationOffset(sciline.Scope[RunType, sc.Variable], sc.Variable):
+    """The difference between the true slope of the sample surface
+    and the sample rotation value in the file."""
+
+
 class DetectorRotation(sciline.Scope[RunType, sc.Variable], sc.Variable):
     """The rotation of the detector relative to the horizon"""