[evt.modules] add xtalk corrector placeholder

src/pygama/evt/modules/geds.py

@@ -0,0 +1,46 @@
+"""Event processors for HPGe data."""
+
+from __future__ import annotations
+
+from collections.abc import Sequence
+
+from lgdo import lh5, types
+
+from .. import utils
+
+
+def apply_xtalk_correction(
+    datainfo: utils.DataInfo,
+    tcm: utils.TCMData,
+    table_names: Sequence[str],
+    *,
+    energy_observable: types.VectorOfVectors,
+    rawids: types.VectorOfVectors,
+    xtalk_matrix_filename: str,
+) -> types.VectorOfVectors:
+    """Applies the cross-talk correction to the energy observable.
+
+    The format of `xtalk_matrix_filename` should be...
+
+    Parameters
+    ----------
+    datainfo, tcm, table_names
+        positional arguments automatically supplied by :func:`.build_evt`.
+    energy_observable
+        array of energy values to correct, one event per row. The detector
+        identifier is stored in `rawids`, which has the same layout.
+    rawids
+        array of detector identifiers for each energy in `energy_observable`.
+    xtalk_matrix_filename
+        name of the file containing the cross-talk matrices.
+    """
+    # read in xtalk matrices
+    lh5.read_as("", xtalk_matrix_filename, "ak")
+
+    # do the correction
+    energies_corr = ...
+
+    # return the result as LGDO
+    return types.VectorOfVectors(
+        energies_corr, attrs=utils.copy_lgdo_attrs(energy_observable)
+    )