From 0bb2bd2c37aa738bbc8ef0cbd346b2393d8dfe0e Mon Sep 17 00:00:00 2001
From: Aymeric Galan <aymeric.galan@gmail.com>
Date: Mon, 15 Apr 2024 09:55:43 +0200
Subject: [PATCH 1/2] Fix position angle computed from central moments
---
coolest/api/util.py | 2 ++
1 file changed, 2 insertions(+)
diff --git a/coolest/api/util.py b/coolest/api/util.py
index fdb42f7..a54347f 100644
--- a/coolest/api/util.py
+++ b/coolest/api/util.py
@@ -214,6 +214,8 @@ def ellipticity_from_moments(light_map, pixel_size):
lambda_2 = (mu_20_ + mu_02_) / 2. - np.sqrt(4*mu_11_**2 + (mu_20_ - mu_02_)**2) / 2.
q = np.sqrt(lambda_2 / lambda_1) # b/a, axis ratio
phi = np.arctan(2. * mu_11_ / (mu_20_ - mu_02_)) / 2. # position angle
+ if mu_02_ > mu_20_:
+ phi += np.pi # makes it consistent angles conventions in COOLEST
return phi, q
From b58f0391c3ba66202ca518c323d5f4324071db52 Mon Sep 17 00:00:00 2001
From: Aymeric Galan <aymeric.galan@gmail.com>
Date: Tue, 16 Apr 2024 09:41:54 +0200
Subject: [PATCH 2/2] Fix angle offset in moments
---
coolest/api/util.py | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/coolest/api/util.py b/coolest/api/util.py
index a54347f..2e41723 100644
--- a/coolest/api/util.py
+++ b/coolest/api/util.py
@@ -215,7 +215,7 @@ def ellipticity_from_moments(light_map, pixel_size):
q = np.sqrt(lambda_2 / lambda_1) # b/a, axis ratio
phi = np.arctan(2. * mu_11_ / (mu_20_ - mu_02_)) / 2. # position angle
if mu_02_ > mu_20_:
- phi += np.pi # makes it consistent angles conventions in COOLEST
+ phi += np.pi / 2. # makes it consistent angles conventions in COOLEST
return phi, q