Add propagation of stat uncertainty for PA

This commit is contained in:
2025-04-15 17:34:10 +02:00
parent e4acb9755c
commit 042be2bad4

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@@ -1549,23 +1549,36 @@ def compute_pol(I_stokes, Q_stokes, U_stokes, Stokes_cov, header_stokes, s_IQU_s
s_PA_P = np.ones(I_stokes.shape) * fmax
maskP = np.logical_and(mask, P > 0.0)
if s_IQU_stat is not None:
s_P_P[maskP] = (
P[maskP]
/ I_stokes[maskP]
* np.sqrt(
s_IQU_stat[0, 0][maskP]
- 2.0 / (I_stokes[maskP] * P[maskP] ** 2) * (Q_stokes[maskP] * s_IQU_stat[0, 1][maskP] + U_stokes[maskP] * s_IQU_stat[0, 2][maskP])
+ 1.0
/ (I_stokes[maskP] ** 2 * P[maskP] ** 4)
* (
Q_stokes[maskP] ** 2 * s_IQU_stat[1, 1][maskP]
+ U_stokes[maskP] ** 2 * s_IQU_stat[2, 2][maskP] * Q_stokes[maskP] * U_stokes[maskP] * s_IQU_stat[1, 2][maskP]
# If IQU covariance matrix containing only statistical error is given propagate to P and PA
# Catch Invalid value in sqrt when diagonal terms are big
with warnings.catch_warnings(record=True) as _:
s_P_P[maskP] = (
P[maskP]
/ I_stokes[maskP]
* np.sqrt(
s_IQU_stat[0, 0][maskP]
- 2.0 / (I_stokes[maskP] * P[maskP] ** 2) * (Q_stokes[maskP] * s_IQU_stat[0, 1][maskP] + U_stokes[maskP] * s_IQU_stat[0, 2][maskP])
+ 1.0
/ (I_stokes[maskP] ** 2 * P[maskP] ** 4)
* (
Q_stokes[maskP] ** 2 * s_IQU_stat[1, 1][maskP]
+ U_stokes[maskP] ** 2 * s_IQU_stat[2, 2][maskP] * Q_stokes[maskP] * U_stokes[maskP] * s_IQU_stat[1, 2][maskP]
)
)
)
s_PA_P[maskP] = (
90.0
/ (np.pi * I_stokes[maskP] ** 2 * P[maskP] ** 2)
* (
Q_stokes[maskP] ** 2 * s_IQU_stat[2, 2][maskP]
+ U_stokes[maskP] * s_IQU_stat[1, 1][maskP]
- 2.0 * Q_stokes[maskP] * U_stokes[maskP] * s_IQU_stat[1, 2][maskP]
)
)
)
else:
# Approximate Poisson error for P and PA
s_P_P[mask] = np.sqrt(2.0 / N_obs[mask])
s_PA_P[maskP] = s_P_P[maskP] / P[maskP] * 90.0 / np.pi
s_PA_P[maskP] = s_P_P[maskP] / P[maskP] * 90.0 / np.pi
# Catch expected "OverflowWarning" as wrong pixel have an overflowing error
with warnings.catch_warnings(record=True) as _: