rescale nb of random dla

desihub · Dec 4, 2024 · 97f7d47 · 97f7d47
1 parent 038252e
commit 97f7d47
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Showing 2 changed files with 8 additions and 3 deletions.
diff --git a/py/desisim/dla.py b/py/desisim/dla.py
@@ -17,7 +17,7 @@
 
 c_cgs = const.c.to('cm/s').value
 
-def insert_dlas(wave, zem, rstate=None, seed=None, fNHI=None, debug=False, **kwargs):
+def insert_dlas(wave, zem, rstate=None, seed=None, fNHI=None, ndla_rescaling=1.0, **kwargs):
     """ Insert zero, one or more DLAs into a given spectrum towards a source
     with a given redshift
     Args:
@@ -26,6 +26,7 @@ def insert_dlas(wave, zem, rstate=None, seed=None, fNHI=None, debug=False, **kwa
         rstate (numpy.random.rstate, optional): for random numberes
         seed (int, optional):
         fNHI (spline): f_NHI object
+        ndla_rescaling (float): the average number of DLAs drawn from a Poison law is rescaled by this number
         **kwargs: Passed to init_fNHI()
 
     Returns:
@@ -59,7 +60,7 @@ def insert_dlas(wave, zem, rstate=None, seed=None, fNHI=None, debug=False, **kwa
     fzdla = interpolate.interp1d(cum_lz/tot_lz, zlya[gdz],
                                  bounds_error=False,fill_value=np.min(zlya[gdz]))#
     # n DLA
-    nDLA = rstate.poisson(tot_lz, 1)
+    nDLA = rstate.poisson(tot_lz * ndla_rescaling, 1)
 
     # Generate DLAs
     dlas = []

diff --git a/py/desisim/scripts/quickquasars.py b/py/desisim/scripts/quickquasars.py
@@ -121,6 +121,9 @@ def parse(options=None):
     parser.add_argument('--dla',type=str,required=False, help="Add DLA to simulated spectra either randonmly\
         (--dla random) or from transmision file (--dla file)")
 
+    parser.add_argument('--ndla-rescaling', type=float, default=1, help='When setting --dla random, the average\
+        number of DLA drawn from a Poison law is rescaled by this number')
+
     parser.add_argument('--balprob',type=float,required=False, help="To add BAL features with the specified probability\
         (e.g --balprob 0.5). Expect a number between 0 and 1 ")
 
@@ -571,7 +574,8 @@ def simulate_one_healpix(ifilename,args,model,obsconditions,decam_and_wise_filte
                 transmission_dla = dla_spec(trans_wave,dlas)
 
             elif args.dla=='random':
-                dlas, transmission_dla = insert_dlas(trans_wave, metadata['Z'][ii], rstate=random_state_just_for_dlas)
+                dlas, transmission_dla = insert_dlas(trans_wave, metadata['Z'][ii],
+                    rstate=random_state_just_for_dlas, ndla_rescaling=args.ndla_rescaling)
                 for idla in dlas:
                    idla['dlaid']+=idd*1000      #Added to have unique DLA ids. Same format as DLAs from file.