AbacusHOD: Moving mock dir creation to run_hod (#187)

* Moved mock_dir.mkdir to run_hod with a condition on write_to_disk (avoid creating empty folder)

* Added a check in staging to make sure the subsample directory exists, and return an explicit error otherwise to avoid an "out of range" IndexError instead

* Added check of the simulation directory (same as the subsample directory one, to make the raised error understandable)

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Remove mkdir (duplicate of makedirs in gen_gal_cat)

* hod: only try to create dirs once

avoid repeated stat

* hod: dir creation condition

* pathlib

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Lehman Garrison <lgarrison@flatironinstitute.org>

Author: 3 people

CHANGES.rst

@@ -1,6 +1,13 @@
 Changelog
 =========
 
+Upcoming
+--------
+
+Improvements
+~~~~~~~~~~~~
+- AbacusHOD: avoid unnecessary mock dir creation [#187]
+
 2.1.1 (2025-07-25)
 ------------------
 

abacusnbody/hod/GRAND_HOD.py

@@ -1,5 +1,6 @@
 import math
 import os
+from pathlib import Path
 import time
 import warnings
 
@@ -1671,6 +1672,21 @@ def gen_gal_cat(
         NFW_draw,
     )
 
+    if write_to_disk and tracers:
+        if rsd:
+            rsd_string = '_rsd'
+        else:
+            rsd_string = ''
+
+        savedir = Path(savedir)
+        if fn_ext is None:
+            outdir = (savedir) / ('galaxies' + rsd_string)
+        else:
+            outdir = (savedir) / ('galaxies' + rsd_string + fn_ext)
+
+        # create directories if not existing
+        os.makedirs(outdir, exist_ok=True)
+
     # how many galaxies were generated and write them to disk
     for tracer in tracers.keys():
         Ncent = HOD_dict[tracer]['Ncent']
@@ -1686,19 +1702,6 @@ def gen_gal_cat(
             if verbose:
                 print('outputting galaxies to disk')
 
-            if rsd:
-                rsd_string = '_rsd'
-            else:
-                rsd_string = ''
-
-            if fn_ext is None:
-                outdir = (savedir) / ('galaxies' + rsd_string)
-            else:
-                outdir = (savedir) / ('galaxies' + rsd_string + fn_ext)
-
-            # create directories if not existing
-            os.makedirs(outdir, exist_ok=True)
-
             # save to file
             # outdict =
             HOD_dict[tracer].pop('Ncent', None)

abacusnbody/hod/abacus_hod.py

@@ -258,10 +258,18 @@ def staging(self):
         simname = Path(self.sim_name)
         sim_dir = Path(self.sim_dir)
         mock_dir = output_dir / simname / ('z%4.3f' % self.z_mock)
-        # create mock_dir if not created
-        mock_dir.mkdir(parents=True, exist_ok=True)
         subsample_dir = Path(self.subsample_dir) / simname / ('z%4.3f' % self.z_mock)
 
+        # Check if the simulation directory exists
+        if not (sim_dir / simname).exists():
+            raise FileNotFoundError(
+                f'Simulation directory {sim_dir / simname} not found.'
+            )
+
+        # Check if the subsample directory exists
+        if not subsample_dir.exists():
+            raise FileNotFoundError(f'Subsample directory {subsample_dir} not found.')
+
         # load header to read parameters
         if self.halo_lc:
             halo_info_fns = [