Modifying phantom dump files
The right way to edit the particle information in a phantom dump file is to use the moddump utility. Compile this from your runtime directory (with a local Makefile written using ~/phantom/scripts/writemake.sh) as follows:
make moddump
This builds a binary called phantommoddump, for which you can write a moddump module to do what you want. The default moddump version is just a “do nothing” operation that you can edit to do what you want. Make your own copy:
cd phantom/src/utils/
cp moddump_default.f90 moddump_mine.f90
Then specify the name of the moddump module in your SETUP block as follows:
ifeq ($(SETUP),blah)
FPPFLAGS=...
...
MODFILE=moddump_mine.f90
Now remake phantommoddump as above, and run it:
$ ./phantommoddump
PhantomSPH: (c) 2007-2018 The Authors
Usage: moddump dumpfilein dumpfileout [time] [outformat]
So for example to edit the dump file dump_00100 and reset the time in the modified file to zero, you would use:
./phantommoddump dump_00100 newdump_00000 0.0
Handling of input file options
For convenience, phantommoddump also creates a .in file. The rules for this are:
First read the .in file with the prefix of the INPUT file if it exists (e.g. dump.in in the above example)
Then read the .in file with the prefix of the OUTPUT file in case it already exists (e.g. newdump.in in the above example)
Write a new .in file with the prefix of the OUTPUT file (e.g. newdump.in)
So the correct usage for phantommoddump is to perform the moddump operation in the same directory as the .in file corresponding to the prefix of the INPUT file. This way, the output .in file will be identical, modified as desired by changes in your moddump module. Otherwise, you will get a .in file with the code defaults which may be different to the settings used in your previous calculation.
For other useful tools, see the full list of Phantom utilities.