Support event-mode monitors

Add WavelengthBins for event mode monitor binning

Add docstring

Author: SimonHeybrock

src/ess/dream/workflow.py

@@ -30,6 +30,7 @@
     TofMask,
     TwoThetaMask,
     VanadiumRun,
+    WavelengthBins,
     WavelengthMask,
 )
 from ess.reduce import time_of_flight
@@ -90,6 +91,7 @@ def default_parameters() -> dict:
         AccumulatedProtonCharge[VanadiumRun]: charge,
         AccumulatedProtonCharge[EmptyCanRun]: charge,
         TofMask: None,
+        WavelengthBins: sc.linspace('wavelength', 0.0, 10.0, 1000, unit='angstrom'),
         WavelengthMask: None,
         TwoThetaMask: None,
         CaveMonitorPosition: sc.vector([0.0, 0.0, -4220.0], unit='mm'),

src/ess/powder/conversion.py

@@ -25,6 +25,7 @@
     MonitorType,
     RunType,
     SampleRun,
+    WavelengthBins,
     WavelengthMonitor,
 )
 
@@ -246,15 +247,27 @@ def convert_reduced_to_empty_can_subtracted_tof(
 
 
 def convert_monitor_to_wavelength(
-    monitor: MonitorTofData[RunType, MonitorType],
+    monitor: MonitorTofData[RunType, MonitorType], wavelength: WavelengthBins
 ) -> WavelengthMonitor[RunType, MonitorType]:
+    """
+    Convert monitor data with time-of-flight coordinate to wavelength.
+
+    Parameters
+    ----------
+    monitor:
+        Monitor data with time-of-flight coordinate.
+    wavelength:
+        Bins for the wavelength coordinate. This will be used ONLY if the monitor is
+        recorded in event mode. For histogrammed monitors no rebinning is performed.
+    """
     graph = {
         **scn.conversion.graph.beamline.beamline(scatter=False),
         **scn.conversion.graph.tof.elastic("tof"),
     }
-    return WavelengthMonitor[RunType, MonitorType](
-        monitor.transform_coords("wavelength", graph=graph, keep_intermediate=False)
-    )
+    mon = monitor.transform_coords("wavelength", graph=graph, keep_intermediate=False)
+    if mon.bins is not None:
+        mon = mon.hist(wavelength=wavelength, dim=mon.dims)
+    return WavelengthMonitor[RunType, MonitorType](mon)
 
 
 providers = (

src/ess/powder/types.py

@@ -63,6 +63,9 @@
 CalibrationFilename = NewType("CalibrationFilename", str | None)
 """Filename of the instrument calibration file."""
 
+WavelengthBins = NewType("WavelengthBins", sc.Variable)
+"""Bin edges for wavelength, used to bin event-mode monitors."""
+
 DspacingBins = NewType("DspacingBins", sc.Variable)
 """Bin edges for d-spacing."""