simplify detector object. Add efficiency libraries and lookup interpolators

src/pg_rad/utils/interpolators.py

@@ -0,0 +1,56 @@
+from importlib.resources import files
+
+import numpy as np
+from pandas import read_csv
+from scipy.interpolate import interp1d, CubicSpline
+
+from pg_rad.configs.filepaths import ATTENUATION_TABLE
+
+
+def get_mass_attenuation_coeff(*args) -> float:
+    csv = files('pg_rad.data').joinpath(ATTENUATION_TABLE)
+    data = read_csv(csv)
+    x = data["energy_mev"].to_numpy()
+    y = data["mu"].to_numpy()
+    f = interp1d(x, y)
+    return f(*args)
+
+
+def get_field_efficiency(name: str, energy_keV: float) -> float:
+    csv = files('pg_rad.data.field_efficiencies').joinpath(name+'.csv')
+    data = read_csv(csv)
+    data = data.groupby("energy_keV", as_index=False).mean()
+    x = data["energy_keV"].to_numpy()
+    y = data["field_efficiency_m2"].to_numpy()
+    f = CubicSpline(x, y)
+    return f(energy_keV)
+
+
+def get_angular_efficiency(name: str, energy_keV: float, *angle: float):
+    csv = files('pg_rad.data.angular_efficiencies').joinpath(name+'.csv')
+    data = read_csv(csv)
+
+    # check all energies at which angular eff. is available for this detector.
+    # this is done within 1% tolerance
+    energy_cols = [col for col in data.columns if col != "angle"]
+    energies = np.array([float(col) for col in energy_cols])
+    rel_diff = np.abs(energies - energy_keV) / energies
+    match_idx = np.where(rel_diff <= 0.01)[0]
+
+    if len(match_idx) == 0:
+        raise NotImplementedError(
+            f"No angular efficiency defined for {energy_keV} keV "
+            f"in detector '{name}'. Available: {energies}"
+        )
+
+    best_idx = match_idx[np.argmin(rel_diff[match_idx])]
+    selected_energy_col = energy_cols[best_idx]
+
+    x = data["angle"].to_numpy()
+    y = data[selected_energy_col].to_numpy()
+    idx = np.argsort(x)
+    x = x[idx]
+    y = y[idx]
+    f = interp1d(x, y)
+
+    return f(angle)