From 7d17a10ad32cadb25d5ca78c149e5704c3c20782 Mon Sep 17 00:00:00 2001
From: Thomas Williams <32936518+thomaswilliamsastro@users.noreply.github.com>
Date: Thu, 18 Jun 2026 14:08:07 +0100
Subject: [PATCH] overwrite_min_loops

This PR adds a ``force_overwrite_min_loops`` parameter that means we don't necessarily need to do some minimum number of loops. Currently, this only applies if there's no model flux after the first iteration, or if there's no flux change between loops, but adds an option to extend this to other criteria
---
 CHANGELOG.md                          |  1 +
 phangsPipeline/casaImagingRoutines.py | 20 ++++++++++++++++++--
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3689722f..9fcea06a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Refactored logging, and added tests (#338).
 - Updated bespoke sdintimaging task, to align with latest CASA version (#347).
+- If we don't have any model flux, then overwrite minimum number of major cycles (#359).
 
 ### Fixed
 
diff --git a/phangsPipeline/casaImagingRoutines.py b/phangsPipeline/casaImagingRoutines.py
index 64662f90..00cafda5 100644
--- a/phangsPipeline/casaImagingRoutines.py
+++ b/phangsPipeline/casaImagingRoutines.py
@@ -957,6 +957,10 @@ def clean_loop(
         previous_flux = current_flux
         current_flux = model_stats['sum'][0]
 
+        # In some cases, we may want to overwrite forcing a
+        # minimum number of loops
+        force_overwrite_min_loops = False
+
         delta_flux = (current_flux - previous_flux)
         if use_absolute_delta:
             delta_flux = abs(delta_flux)
@@ -968,6 +972,9 @@ def clean_loop(
         if np.isnan(frac_delta_flux) and loop > 0:
             frac_delta_flux = 0
 
+            # At this point, doing more loops won't change anything
+            force_overwrite_min_loops = True
+
         # Check whether the model flux convergence criteria is met
 
         if convergence_fracflux is not None:
@@ -986,6 +993,12 @@ def clean_loop(
             if cumulative_niter >= max_total_niter:
                 proceed = False
 
+        # If there's no change in the flux, then running for more loops
+        # won't do anything
+        if delta_flux == 0:
+            proceed = False
+            force_overwrite_min_loops = True
+
         # If requested, stop if the integrated model flux becomes
         # negative.
 
@@ -1034,12 +1047,15 @@ def clean_loop(
             noise_conv = None
 
         # Enforce minimum and maximum limits on number of loops. These
-        # override other convergence criteria.
+        # override other convergence criteria in most cases.
 
         if loop >= max_loops:
             proceed = False
         if loop < min_loops:
-            proceed = True
+            if force_overwrite_min_loops:
+                proceed = False
+            else:
+                proceed = True
 
         # Generate a record line and print the current status to the screen