iharm2d_v4 is the 2D version of iharm3d with minimal dependencies. iharm2d_v4 parallelizes computation across all cores of a single node using OpenMP. This means you must have a C compiler with OpenMP. Data is written out to ASCII files and a sample analysis script is provided at files/plot_density.py to get a feel for the output format (One can always browse through core/io.c to get a better sense for the dump output).
TODO: Documentation page for dump format.
One can make the program from the output directory,
$ make -f IHARM2D_v4_DIRECTORY/makefile PROB=PROBLEMwhere IHARM2D_v4_DIRECTORY is the path to your local iharm2d_v4 respository that contains the makefile. PROBLEM is the name of the problem you wish to run. NOTE: This must match the problem name in the prob directory. The makefile by default assumes the GCC as your compiler and that it is in your PATH.
The makefile will produce a directory named build_archive in your output directory. This contains all the source files (source code and header files) and a copy of the executable, harm. The executable is copied over to the output directory. Much like iharm3d, if build_archive already exists, make will prefer an newer/modified files in that directory over their equivalents in the original source. This allows you to modify the source code without disrupting the original repository.
When it comes to modifying parameters, iharm2d_v4 follows the ideology of iharm3d. Compile-time parameters are present in parameters.h located in build_archive while run-time parameters are provided via an additional parameter file param.dat. If you're modifying compile-time parameters (eg: grid size, floors, reconstruction scheme, boundary conditions), you'll have to rerun the make command. A sample param.dat file is provided at prob/PROBLEM/param.dat which must be copied over to your output directory. Run-time parameters include duration of the run, domain size, fluid properties, and any other problem specific parameters.
The problem can be executed by calling the harm executable,
$ ./harm -p param.dat >OUTPUT_LOG_FILEwhere the STDOUT will be redirected to OUTPUT_LOG_FILE. If STDOUT is not redirected, the run-time log will be printed on the terminal.
A density plot of the simulation (overlaid with magnetic field lines) can be generated by running the file files/plot_density.py,
$ python3 path/to/plot_density.py path/to/dumps/directory path/to/output/directory