Running Gmsh once

In this example we will run a gmsh script to generate a mesh file using the GmshRunner class.

Installing gmsh: For this example you will need to have a gmsh executable which can be downloaded and installed from here: https://gmsh.info/#Download

We start by importing what we need for this example.

import time
from pathlib import Path

#pyvale imports
import pyvale.data as dataset
from pyvale.mooseherder import GmshRunner


def main() -> None:

    #%%
    # First we need to create a 'runner' for gmsh which needs to know the path to
    # the gmsh executable. You will need to replace this path with the path to where
    # you have install gmsh on your system.
    gmsh_path = Path.home() / 'gmsh/bin/gmsh'
    gmsh_runner = GmshRunner(gmsh_path)

    #%%
    # Next we grab a gmsh file from pyvale simulation library and we set this as the
    # input file for our runner.
    gmsh_input = dataset.sim_case_gmsh_file_path(case_num=17)
    gmsh_runner.set_input_file(gmsh_input)

    #%%
    # Now we can run gmsh to generate our mesh using the run method, the parse only
    # flag means we will run gmsh head less and not open the gmsh GUI but terminal
    # output will still be written to stdout.
    #
    # We also use our performance timer to time how long our mesh generation takes
    # and then we print this to the console. Note that parallelisation options for
    # gmsh can be controlled in the gmsh .geo script file.
    start_time = time.perf_counter()
    gmsh_runner.run(gmsh_input,parse_only=True)
    run_time = time.perf_counter() - start_time

    print()
    print("-"*80)
    print(f'Gmsh run time = {run_time :.3f} seconds')
    print("-"*80)
    print()

    #%%
    # The GmshRunner and the MooseRunner implement the SimRunner abstract base
    # class. Later on when we will see that we can use this to run a list of
    # different sim runners in order using MooseHerd workflow manager. This allows
    # us to first build our mesh with gmsh and then run a moose simulation using
    # that mesh. We can also implement our own SimRunner's to add additional pre or
    # post processing steps to our simulation chain.


from pyvale.mooseherder import gmsh_availability

if not gmsh_availability().available:
    print("Gmsh is unavailable: skipping this example.")
    print("Install Gmsh and make sure the 'gmsh' executable is on PATH.")
else:
    main()