safe division; decreasing number of randoms since at z ~ 1 becomes co…

…mputationally expensive

abacusnbody/hod/prepare_sim.py

@@ -528,7 +528,7 @@ def prepare_slab(
 
             if len(index_bounds) > 0:
                 # factor of rands to generate
-                rand = 100  # to ensure 12 times more randoms than haloes in the octant.
+                rand = 50  # to ensure 6 times more randoms than haloes in the octant.
                 rand_N = allpos.shape[0] * rand
 
                 # generate randoms in L shape
@@ -591,8 +591,14 @@ def prepare_slab(
         gc.collect()
 
         if halo_lc and len(index_bounds) > 0:
-            Menv[index_bounds] /= rand_norm
-
+            mask = rand_norm == 0.0
+            rand_norm[mask] = 1.0
+            tmp = Menv[index_bounds]
+            tmp /= rand_norm  # fixed (pull request #142)
+            tmp[mask] = 0.0
+            Menv[index_bounds] = tmp
+            del mask
+            gc.collect()
         halos['fenv_rank'] = calc_fenv_opt(Menv, mbins, allmasses)
 
         # compute delta concentration

tests/ref_hod/AbacusSummit_base_c000_ph001-abridged/z2.250/galaxies_rsd/ELGs.dat

@@ -9,15 +9,11 @@
 # - {name: vz, datatype: float64}
 # - {name: mass, datatype: float64}
 # - {name: id, datatype: int64}
-# meta: {A_s: 1.0, Acent: 0, Asat: 0, Bcent: 0, Bsat: 0, Gal_type: ELG, Ncent: 7, Q: 100.0, alpha: 1.0, alpha_c: 0, alpha_s: 1, gamma: 4.12,
+# meta: {A_s: 1.0, Acent: 0, Asat: 0, Bcent: 0, Bsat: 0, Gal_type: ELG, Ncent: 2, Q: 100.0, alpha: 1.0, alpha_c: 0, alpha_s: 1, gamma: 4.12,
 #   ic: 1.0, kappa: 1.0, logM1: 13.53, logM_cut: 11.75, p_max: 0.33, s: 0, s_p: 0, s_r: 0, s_v: 0, sigma: 0.58}
 # schema: astropy-2.0
 x y z vx vy vz mass id
--989.9376978993922 2271.8044883431635 814.4623365958757 -676.4788208007812 200.33482360839844 234.51451110839844 520943135551.90656 1337345
--989.797938586897 2393.4425817463325 900.0504605283132 -310.83984375 226.46484375 -10.9130859375 748723939760.8374 1347781
--989.9722399519769 2436.1243832394684 893.0100597725067 -244.4615020751953 21.344865798950195 -372.9910583496094 1060868004787.8907 1351697
--989.93851790025 2574.3917024073676 494.9816122572673 -60.2254753112793 245.01829528808594 -252.323974609375 1788501129344.1975 1362713
+-989.8515106521996 2597.74790397846 4.456388275794544 416.015625 637.3980712890625 2.5475542545318604 700215064790.4169 1190110
 -989.9779939780151 2595.872235514386 174.58946130616962 279.78515625 405.76171875 682.470703125 594760988767.7638 1364044
--989.8491016637607 2700.924001600403 128.59961886324763 192.24267578125 -99.3597640991211 -54.88894271850586 4730669850376.221 1374058
--989.9346596474115 2712.400836645169 79.9785797238952 346.61865234375 -133.11767578125 -166.9921875 491415994265.56366 1375036
--989.8232582237715 2546.1908703460344 572.2576660921198 618.0 278.25 -720.5 15543930805739.074 1360581
+-989.4958507458637 2541.0769782689267 569.9216546495883 216.75 -925.75 644.5 15543930805739.074 1360581
+-989.5793640317086 2663.630357230081 338.882715370822 -225.5625 -445.25 483.375 9446576130109.27 1370826