Zoom data reduction

docs/examples/zoom.ipynb

@@ -44,8 +44,6 @@
    "source": [
     "import scipp as sc\n",
     "import sciline\n",
-    "import scippneutron as scn\n",
-    "import plopp\n",
     "import esssans as sans\n",
     "import esssans.isis\n",
     "from esssans.types import *"
@@ -242,14 +240,7 @@
     "\n",
     "display(sc.plot({str(key): results[key] for key in monitors}, norm='log'))\n",
     "\n",
-    "display(\n",
-    "    scn.instrument_view(\n",
-    "        results[MaskedData[SampleRun]].hist(),\n",
-    "        pixel_size=0.0075,\n",
-    "        norm='log',\n",
-    "        camera=plopp.graphics.Camera(position=(0, 0, 22)),\n",
-    "    )\n",
-    ")\n",
+    "display(sans.isis.plot_instrument(results[MaskedData[SampleRun]]))\n",
     "\n",
     "parts = {str(key): results[key] for key in parts}\n",
     "parts = {key: val if val.bins is None else val.hist() for key, val in parts.items()}\n",

src/esssans/isis/__init__.py

@@ -12,6 +12,7 @@
 from .common import transmission_from_background_run, transmission_from_sample_run
 from .io import CalibrationFilename, DataFolder, Filename, PixelMaskFilename
 from .masking import PixelMask
+from .visualization import plot_instrument
 
 providers = (
     (
@@ -40,4 +41,5 @@
     'providers',
     'transmission_from_background_run',
     'transmission_from_sample_run',
+    'plot_instrument',
 ]

src/esssans/isis/data.py

@@ -25,7 +25,7 @@
         'ModeratorStdDev_TS2_SANS_LETexptl_07Aug2015.txt': 'md5:5fc389340d453b9095a5dfcc33608dae',  # noqa: E501
         # ISIS user file configuring the data reduction
         'USER_ZOOM_Cabral_4m_TJump_233G_8x8mm_Small_BEAMSTOP_v1_M5.toml': 'md5:4423ecb7d924c79711aba5b0a30a23e7',  # noqa: E501
-        # Mask files
+        # 7 pixel mask files for the ZOOM00034786.nxs run
         'andru_test.xml': 'md5:c59e0c4a80640a387df7beca4857e66f',
         'left_beg_18_2.xml': 'md5:5b24a8954d4d8a291f59f5392cd61681',
         'right_beg_18_2.xml': 'md5:fae95a5056e5f5ba4996c8dff83ec109',

src/esssans/isis/visualization.py

@@ -0,0 +1,43 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright (c) 2024 Scipp contributors (https://github.com/scipp)
+"""
+Plotting functions for ISIS data.
+"""
+from typing import Any
+
+import scipp as sc
+
+
+def plot_instrument(da: sc.DataArray, pixels_per_tube: int = 512, **kwargs: Any) -> Any:
+    """
+    Plot a 2-D instrument view of a data array.
+
+    This is an alternative to the `scn.instrument_view` function, avoiding the 3-D
+    rendering of the instrument. The exact X and Y coordinates of the pixels are
+    used for the 2-D plot.
+
+    Parameters
+    ----------
+    da:
+        The data array to plot. Must have a 'position' coord and a single dimension.
+    pixels_per_tube:
+        The number of pixels per tube. Defaults to 512.
+    kwargs:
+        Additional arguments passed to `sc.plot`.
+    """
+    if da.bins is not None:
+        da = da.hist()
+    da.coords['x'] = da.coords['position'].fields.x.copy()
+    da.coords['y'] = da.coords['position'].fields.y.copy()
+    folded = da.fold(da.dim, sizes={'y': -1, 'x': pixels_per_tube})
+    y = folded.coords['y']
+    if sc.all(y.min('x') == y.max('x')):
+        folded.coords['y'] = y.min('x')
+    else:
+        raise ValueError(
+            'Cannot plot 2-D instrument view of data array with non-constant '
+            'y coordinate along tubes. Use scippneutron.instrument_view instead.'
+        )
+    plot_kwargs = dict(aspect='equal', norm='log', figsize=(6, 10))
+    plot_kwargs.update(kwargs)
+    return folded.plot(**plot_kwargs)