Compile-time configuration

Phantom uses a mix of compile-time and run-time configuration. The run-time configuration is specified in the input file (blah.in). Compile-time options are as follows:

Simple things can be changed on the command line. To change the maximum number of particles use:

make SETUP=disc MAXP=10000000

Setup block

The compile-time configuration of Phantom is specified using the SETUP block in build/Makefile_setups. For example the default disc setup is “disc”:

ifeq ($(SETUP), disc)
#   locally isothermal gas disc
    FPPFLAGS= -DDISC_VISCOSITY
    SETUPFILE= setup_disc.f90
    ANALYSIS= analysis_disc.f90
    ISOTHERMAL=yes
    KNOWN_SETUP=yes
    MULTIRUNFILE= multirun.f90
    IND_TIMESTEPS=yes
endif

The choice of C preprocessor flags (FPPFLAGS=) can be used to specify particular physics. Otherwise these are specified using variables in this block as follows:

Pre-cooked setups

For many applications a pre-cooked SETUP block already exists. View the full list here. You can also override any of the compile-time settings manually, using the options below.

Code modules

Variable	Setting	Default value	Description
SETUPFILE	.f90 file(s)	setup_unifdis.F90	The setup routine and any auxiliary routines needed by phantomsetup
LINKLIST	.f90 file(s)	linklist.F90	The neighbour finding algorithm (fixed grid, fixed cylindrical grid or kdtree)
ANALYSIS	.f90 file(s)	analysis_dtheader.f90	(optional) The analysis routine and any auxiliary routines used by the phantomanalysis utility
SRCTURB	.f90 file(s)	forcing.f90	(optional) Turbulence driving routine (triggers -DDRIVING)
SRCINJECT	.f90 file(s)	inject_rochelobe.f90	(optional) Module handling particle injection (triggers -DINJECT_PARTIC LES)
MODFILE	.f90 file(s)	moddump.f90	(optional) Routine used by moddump utility (to modify an existing dump file)

Code performance and accuracy

Variable	Setting	Default value	Description
MPI	yes/no/openmpi/ zen/apac	no	compile with MPI parallelisation
OPENMP	yes/no	yes	compile with openMP parallelisation
IND_TIMESTEPS	yes/no	no	use individual timesteps or not
DOUBLEPRECISION	yes/no	yes	use 8-byte reals (no=4 byte)
DEBUG	yes/no	no	turns on debugging flags (slow)

Memory usage

Variable	Setting	Default value	Description
MAXP	integer	1000000	maximum number of particles (array size)
MAXPTMASS	integer	2	maximum number of point mass particles (array size)
MAXNEIGH	integer	same as maxp	maximum size of neighbour arrays (default is safest but can be lower to save memory)
NCELLSMAX	integer	same as maxp	maximum number of cells in fixed-grid neighbour finding

Physics

Variable	Setting	Default value	Description
PERIODIC	yes/no	no	periodic boundaries
ISOTHERMAL	yes/no	no	determines whether or not to store thermal energy
GRAVITY	yes/no	no	use self-gravity or not
MHD	yes/no	no	use magnetohydrodyn amics or not
DUST	yes/no	no	use dust algorithms or not
H2CHEM	yes/no	no	use H2 chemistry or not
DISC_VISCOSITY	yes/no	no	apply artificial viscosity to both approaching and receding particles and multiply by h/rij
CONST_AV	yes/no	no	use a constant artificial viscosity parameter instead of the Morris & Monaghan switch
CONST_ARTRES	yes/no	no	use a constant artificial resistivity parameter instead of the Tricco & Price switch (MHD only)
CURLV	yes/no	no	store curl v and write it to full dump files
USE_STRAIN_TENS OR	yes/no	no	determines whether or not strain tensor is stored, and therefore whether physical viscosity is done using two first derivatives or two second derivatives (see Lodato & Price 2010)
DUSTGROWTH	yes/no	no	use dust growth (and/or fragmentation) prescription from Stepinski & Valageas (1997) for two-fluid algorithm or not

Examples

For example, to set individual timesteps on the command line:

make IND_TIMESTEPS=yes

or put this in the SETUP block:

ifeq ($(SETUP), disc)
    ...
    IND_TIMESTEPS=yes