POT3D: High Performance Potential Field Solver Predictive Science Inc. www.predsci.com

############################### HOW TO BUILD: ###############################

Modify "build.sh" to set the proper HDF5 library paths/flags and compiler flags for your system. Then, simply run "./build.sh".
See comments inside build.sh for more details.

################################### HOW TO RUN SMALL TEST VALIDATION: ###################################

After building the code, simply run "./validate.sh". This will perform 2 runs of a small case using 1 and 2 MPI ranks respectively.

The runs are performed in "testsuite/validation/run/" and the second run overwrites the first.

Each result will be checked against a reference solution (in /runs/validation/validation) and a PASS/FAIL message will be displayed.

############################### POT3D DOCUMENTATION ###############################

POT3D uses a namelist in an input file called "pot3d.dat" to set all parameters of a run. It also requires an input 2D data set in HDF5 format to use for the lower boundary condition. This file in the tests provided are called 'br_input_.h5' where is the specific test name.

Simply run the code as:

mpiexec -np ./pot3d (or ibrun, mpirun, etc).

For CPU runs, please ensure "ifprec=2" is set in pot3d.dat in order to ensure optimal computation speed.

For standard cases, one should launch the code such that the number of MPI ranks per node is equal to the number of GPUs per node e.g.

mpiexec -np --ntasks-per-node 4 ./pot3d or mpiexec -np --npersocket 2 ./pot3d etc.

To run efficiently, it is critical that "ifprec=1" is set in pot3d.dat.

At the end of the run, POT3D (as setup in the tests) outputs the following files:

pot3d.out An output log showing grid information and derived magnetic energy. timing.out Results of the MPI timing recorded in the code.

We have included a validation script (pot3d_validate.sh) that takes two pot3d.out files and compares the magnetic energy values in them. If they match, the test passes, if they do not, their values are displayed for further investigation.

Example: ./pot3d_validate.sh ./runs/test/run/pot3d.out ./runs/test/validation/pot3d.out

Within each test directory, there is a "validation" folder with the pot3d.out file for that run in it.

Information on the computer, compiler, and setup used to generate the validation data is in the "validation_run_information.txt" file in each validation folder.

To estimate how many GB of RAM is needed for a run, compute: nrntnp815/1024/1000/1000