fix: type and better name and docs

src/esssans/normalization.py

@@ -65,28 +65,32 @@ def solid_angle_rectangular_approximation(
     )
 
 
-def solid_angle_rectangular_approximation_cylinder(
+def solid_angle(
+    data: CalibratedMaskedData[RunType],
     detector: DetectorGeometry[RunType],
 ) -> SolidAngle[RunType]:
     """
-    Solid angle computed from cylindrical pixels.
+    Solid angle for cylindrical pixels.
 
-    Note that this approximation is only valid when the distance between sample
-    and pixel is much larger than the length or the radius of the pixel.
+    Note that the approximation is valid when the distance from sample
+    to pixel is much larger than the length or the radius of the pixels.
 
     Parameters
     ----------
+    data:
+        The DataArray that contains the positions of the detector pixels in coords.
+        The positions must be in the sample reference frame.
+
     detector:
         The DataGroup that contains the geometry of the detector.
-        Must contain pixel_shape, the transformation to the sample reference frame
-        and the position (center) of each pixel.
+        Must contain pixel_shape and the transformation from the
+        local reference frame of the detector to the sample reference frame.
 
     Returns
     -------
     :
         The solid angle of the detector pixels, as viewed from the sample position.
     """
-
     face_1_center, face_1_edge, face_2_center = (
         detector['pixel_shape']['vertices']['vertex', i] for i in range(3)
     )
@@ -98,9 +102,7 @@ def solid_angle_rectangular_approximation_cylinder(
 
     return SolidAngle[RunType](
         approximate_solid_angle_for_cylinder_shaped_pixel_of_detector(
-            # Is there a way to get the positions of
-            # the pixels without going through the events?
-            pixel_position=detector['larmor_detector_events'].coords['position'],
+            pixel_position=data.coords['position'],
             cylinder_axis=cylinder_axis,
             radius=radius,
             length=length,

src/esssans/types.py

@@ -106,7 +106,7 @@ class Filename(sciline.Scope[RunType, str], str):
 """Direct beam after resampling to required wavelength bins"""
 
 
-class DetectorGeometry(sciline.Scope[RunType, sc.DataGroup], sc.DataArray):
+class DetectorGeometry(sciline.Scope[RunType, sc.DataGroup], sc.DataGroup):
     """Geometry of the detector from description in nexus file."""