Merge pull request #226 from cta-observatory/pixel_table

Add module_id, hardware_pixel_id, module_pixel_index to camera geometry table

src/ctapipe_io_lst/__init__.py

@@ -37,6 +37,7 @@
 from .version import __version__
 from .calibration import LSTR0Corrections
 from .event_time import EventTimeCalculator, cta_high_res_to_time
+from .pixels import get_pixel_table
 from .pointing import PointingSource
 from .anyarray_dtypes import (
     CDTS_AFTER_37201_DTYPE,
@@ -100,9 +101,8 @@ def get_channel_info(pixel_status):
 
 def load_camera_geometry():
     ''' Load camera geometry from bundled resources of this repo '''
-    with as_file(files("ctapipe_io_lst") / "resources/LSTCam.camgeom.fits.gz") as path:
-        Provenance().add_input_file(path, role="CameraGeometry")
-        cam = CameraGeometry.from_table(path)
+    pixel_table = get_pixel_table()
+    cam = CameraGeometry.from_table(pixel_table)
     cam.frame = CameraFrame(focal_length=OPTICS.effective_focal_length)
     return cam
 

src/ctapipe_io_lst/calibration.py

@@ -24,23 +24,17 @@
     N_GAINS, N_PIXELS, N_MODULES, N_SAMPLES, LOW_GAIN, HIGH_GAIN,
     N_PIXELS_MODULE, N_CAPACITORS_PIXEL, N_CAPACITORS_CHANNEL,
     CLOCK_FREQUENCY_KHZ,
-    CHANNEL_ORDER_LOW_GAIN, CHANNEL_ORDER_HIGH_GAIN, N_CHANNELS_MODULE,
+    N_CHANNELS_MODULE,
     PIXEL_INDEX, PixelStatus
 )
 
+from .pixels import pixel_channel_indices
+
 __all__ = [
     'LSTR0Corrections',
 ]
 
 
-@lru_cache()
-def pixel_channel_indices(n_modules):
-    module_index = np.repeat(np.arange(n_modules), 7)
-    low_gain = module_index * N_CHANNELS_MODULE + np.tile(CHANNEL_ORDER_LOW_GAIN, n_modules)
-    high_gain = module_index * N_CHANNELS_MODULE + np.tile(CHANNEL_ORDER_HIGH_GAIN, n_modules)
-    return low_gain, high_gain
-
-
 def get_first_capacitors_for_pixels(first_capacitor_id, expected_pixel_id=None):
     '''
     Get the first capacitor for each pixel / gain

src/ctapipe_io_lst/pixels.py

@@ -0,0 +1,70 @@
+import numpy as np
+from functools import lru_cache
+from astropy.table import Table
+from importlib.resources import files, as_file
+
+from ctapipe.core import Provenance
+
+from .constants import N_PIXELS_MODULE, CHANNEL_ORDER_LOW_GAIN, CHANNEL_ORDER_HIGH_GAIN, N_CHANNELS_MODULE
+
+
+@lru_cache()
+def pixel_channel_indices(n_modules):
+    """Get index into first_capacitor_id or each channel, pixel"""
+    return _pixel_channel_indices(np.arange(n_modules))
+
+
+def _pixel_channel_indices(module_id_map):
+    module = np.repeat(module_id_map, N_PIXELS_MODULE)
+    n_modules = len(module_id_map)
+    low_gain = module * N_CHANNELS_MODULE + np.tile(CHANNEL_ORDER_LOW_GAIN, n_modules)
+    high_gain = module * N_CHANNELS_MODULE + np.tile(CHANNEL_ORDER_HIGH_GAIN, n_modules)
+    return low_gain, high_gain
+
+
+def get_pixel_table_from_camera_config(config):
+    """
+    Construct a table of pixel / module ids from the mappings in CameraConfiguration
+    """
+    if hasattr(config, "pixel_id_map"):
+        # new R1v1.CameraConfiguration
+        pixel_id_map = config.pixel_id_map
+        module_id_map = config.module_id_map
+    else:
+        # old ProtoR1.CameraConfiguration
+        pixel_id_map = config.expected_pixels_id
+        module_id_map = config.lstcam.expected_modules_id
+
+    n_modules = len(module_id_map)
+    n_pixels = len(pixel_id_map)
+
+    chip_lg, chip_hg = _pixel_channel_indices(module_id_map)
+
+    pixel_index = np.arange(n_pixels)
+    # the pixel data arrives in module groups, the module id of each group
+    # is in module_id_map. Repeat to have the module_id of each pixel
+    module_id = np.repeat(module_id_map, N_PIXELS_MODULE)
+
+    # pixels inside one module are ordered by module_pixel_index
+    module_pixel_index = np.tile(np.arange(N_PIXELS_MODULE), n_modules)
+    hardware_pixel_id = module_id * N_PIXELS_MODULE + module_pixel_index
+
+    table = Table(dict(
+        pixel_id=pixel_id_map,
+        pixel_index=pixel_index,
+        module_id=module_id,
+        module_pixel_index=module_pixel_index,
+        hardware_pixel_id=hardware_pixel_id,
+        drs4_chip_hg=chip_hg,
+        drs4_chip_lg=chip_lg,
+    ))
+
+    table.sort("pixel_id")
+    return table
+
+
+def get_pixel_table():
+    """Load pixel information from bundled camera geometry file"""
+    with as_file(files("ctapipe_io_lst") / "resources/LSTCam.camgeom.fits.gz") as path:
+        Provenance().add_input_file(path, role="CameraGeometry")
+        return Table.read(path)

src/ctapipe_io_lst/tests/test_pixels.py

@@ -0,0 +1,31 @@
+import os
+from pathlib import Path
+
+import numpy as np
+import protozfits
+import pytest
+
+test_data = Path(os.getenv('LSTCHAIN_TEST_DATA', 'test_data')).absolute()
+test_file_protor1 = test_data / "real/R0/20200218/LST-1.1.Run02008.0000_first50.fits.fz"
+test_file_r1v1 = test_data / "real/R0/20231219/LST-1.1.Run16255.0000_first50.fits.fz"
+
+
+@pytest.mark.parametrize("path", (test_file_protor1, test_file_r1v1))
+def test_get_pixel_table_from_camera_config(path):
+    from ctapipe_io_lst.pixels import get_pixel_table_from_camera_config
+
+    with protozfits.File(str(path)) as f:
+        config = getattr(f, "CameraConfig", getattr(f, "CameraConfiguration", None))[0]
+
+    table = get_pixel_table_from_camera_config(config)
+
+    np.testing.assert_array_equal(np.unique(table["module_id"]), np.arange(265))
+
+    # check relationship between hardware_pixel_id and position in module
+    np.testing.assert_array_equal(
+        table["module_id"] * 7 + table["module_pixel_index"],
+        table["hardware_pixel_id"],
+    )
+
+    # check we have sorted by pixel id
+    np.testing.assert_array_equal(table["pixel_id"], np.arange(1855))