Gravitational potential calculation (#60)

* Rename file

* add velocity field

* Add velcoity field

* Move smoothening

* Add verbosity flags

* remove blank

* Simplify paths

* Add potential calculation

* Update paths

* Add potential field

* Add potential calculation

* Move away sky matching

* Move interpolation functions

* Update nbs

scripts/field_derived.py

@@ -0,0 +1,78 @@
+# Copyright (C) 2022 Richard Stiskalek
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation; either version 3 of the License, or (at your
+# option) any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
+# Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+"""
+MPI script to calculate density field-derived fields in the CSiBORG
+simulations' final snapshot.
+"""
+from argparse import ArgumentParser
+from datetime import datetime
+from distutils.util import strtobool
+
+import numpy
+from mpi4py import MPI
+
+try:
+    import csiborgtools
+except ModuleNotFoundError:
+    import sys
+    sys.path.append("../")
+    import csiborgtools
+
+comm = MPI.COMM_WORLD
+rank = comm.Get_rank()
+nproc = comm.Get_size()
+verbose = nproc == 1
+
+parser = ArgumentParser()
+parser.add_argument("--ics", type=int, nargs="+", default=None,
+                    help="IC realisations. If `-1` processes all simulations.")
+parser.add_argument("--kind", type=str, choices=["potential", "velocity"],
+                    help="What derived field to calculate?")
+parser.add_argument("--MAS", type=str, choices=["NGP", "CIC", "TSC", "PCS"])
+parser.add_argument("--grid", type=int, help="Grid resolution.")
+parser.add_argument("--in_rsp", type=lambda x: bool(strtobool(x)),
+                    help="Calculate from the RSP density field?")
+args = parser.parse_args()
+paths = csiborgtools.read.CSiBORGPaths(**csiborgtools.paths_glamdring)
+
+if args.ics is None or args.ics[0] == -1:
+    ics = paths.get_ics()
+else:
+    ics = args.ics
+
+
+for i in csiborgtools.fits.split_jobs(len(ics), nproc)[rank]:
+    nsim = ics[i]
+    if verbose:
+        print(f"{datetime.now()}: rank {rank} working on simulation {nsim}.",
+              flush=True)
+    nsnap = max(paths.get_snapshots(nsim))
+    box = csiborgtools.read.BoxUnits(nsnap, nsim, paths)
+    density_gen = csiborgtools.field.DensityField(box, args.MAS)
+
+    rho = numpy.load(paths.field_path("density", args.MAS, args.grid, nsim,
+                                      args.in_rsp))
+    rho = density_gen.overdensity_field(rho)
+
+    if args.kind == "potential":
+        gen = csiborgtools.field.PotentialField(box, args.MAS)
+    else:
+        raise RuntimeError(f"Field {args.kind} is not implemented yet.")
+
+    field = gen(rho)
+    fout = paths.field_path("potential", args.MAS, args.grid, nsim,
+                            args.in_rsp)
+    print(f"{datetime.now()}: rank {rank} saving output to `{fout}`.")
+    numpy.save(fout, field)

scripts/field_fromparts.py

@@ -38,12 +38,16 @@ verbose = nproc == 1
 parser = ArgumentParser()
 parser.add_argument("--ics", type=int, nargs="+", default=None,
                     help="IC realisations. If `-1` processes all simulations.")
+parser.add_argument("--kind", type=str, choices=["density", "velocity"],
+                    help="Calculate the density or velocity field?")
+parser.add_argument("--MAS", type=str, choices=["NGP", "CIC", "TSC", "PCS"],
+                    help="Mass assignment scheme.")
 parser.add_argument("--grid", type=int, help="Grid resolution.")
 parser.add_argument("--in_rsp", type=lambda x: bool(strtobool(x)),
                     help="Calculate the density field in redshift space?")
-parser.add_argument("--MAS", type=str, choices=["NGP", "CIC", "TSC", "PCS"])
 args = parser.parse_args()
 paths = csiborgtools.read.CSiBORGPaths(**csiborgtools.paths_glamdring)
+mpart = 1.1641532e-10  # Particle mass in CSiBORG simulations.
 
 if args.ics is None or args.ics[0] == -1:
     ics = paths.get_ics()
@@ -59,11 +63,14 @@ for i in csiborgtools.fits.split_jobs(len(ics), nproc)[rank]:
     nsnap = max(paths.get_snapshots(nsim))
     box = csiborgtools.read.BoxUnits(nsnap, nsim, paths)
     parts = csiborgtools.read.read_h5(paths.particles_path(nsim))["particles"]
-    density_generator = csiborgtools.field.DensityField(box, args.MAS)
 
-    rho = density_generator(parts, args.grid, in_rsp=args.in_rsp,
-                            verbose=verbose)
+    if args.kind == "density":
+        gen = csiborgtools.field.DensityField(box, args.MAS)
+        field = gen(parts, args.grid, in_rsp=args.in_rsp, verbose=verbose)
+    else:
+        gen = csiborgtools.field.VelocityField(box, args.MAS)
+        field = gen(parts, args.grid, mpart, verbose=verbose)
 
-    fout = paths.density_field_path(args.MAS, nsim, args.in_rsp)
+    fout = paths.field_path(args.kind, args.MAS, args.grid, nsim, args.in_rsp)
     print(f"{datetime.now()}: rank {rank} saving output to `{fout}`.")
-    numpy.save(fout, rho)
+    numpy.save(fout, field)