bug fix: crash when --catalog not given

run_sim.py

@@ -85,9 +85,10 @@ def run_sim():
     # Initialize the simulation
     if args.catalog is not None:
         catalog_module = importlib.import_module('Catalog.'+args.catalog)
+        obs = Observation(config=config, Catalog=catalog_module.Catalog, work_dir=config['work_dir'], data_dir=config['data_dir'])
     else:
         catalog_module = None
-    obs = Observation(config=config, Catalog=catalog_module.Catalog, work_dir=config['work_dir'], data_dir=config['data_dir'])
+        obs = Observation(config=config, Catalog=None, work_dir=config['work_dir'], data_dir=config['data_dir'])
     
     # Run simulation
     obs.runExposure_MPI_PointingList(

test_C6.sh

@@ -4,8 +4,8 @@ date
 
 python3 /public/home/fangyuedong/project/csst-simulation/run_sim.py \
     --config_file config_overall.yaml \
-    --catalog C6_50sqdeg \
-    -c /public/home/fangyuedong/project/csst-simulation/config
+    -c /public/home/fangyuedong/project/csst-simulation/config \
+    --catalog C6_50sqdeg 
 
 # python3 /share/home/fangyuedong/20231211/csst-simulation/run_sim.py \
 #     --config_file config_C6_dev.yaml \