Adding a First Task

In this section, we’ll add the first actual task to our new category, following the structure of the overflow default test. We’ll create a default task that sets up the mesh for now but will eventually also create an initial condition, runs a short forward integration, and generates a plot for quick inspection.

Adding a `default` Task

We’ll add a task called default to my_overflow by making a default package within polaris/tasks/ocean/my_overflow. First, create the directory and an empty __init__.py file:

$ mkdir polaris/tasks/ocean/my_overflow/default
$ touch polaris/tasks/ocean/my_overflow/default/__init__.py

Now, let’s create the Default class in this file. This class should inherit from polaris.Task and add the necessary steps (init for now, more to come later in the tutorial). The constructor should take component and any shared steps (init in this case). It is frequently useful to include other parameters like a directory the task will live in (indir) and any other parameters (like the grid resolution) that may distinguish different versions of the task from one another. Here’s our example:

from polaris import Task as Task


class Default(Task):
    """
    The default "my overflow" test case simply creates the mesh and
    initial condition, then performs a short forward run on 4 cores.
    """

    def __init__(self, component, indir, init):
        """
        Create the test case

        Parameters
        ----------
        component : polaris.ocean.Ocean
            The ocean component that this task belongs to

        indir : str
            The directory the task is in, to which ``name`` will be appended

        init : polaris.tasks.ocean.my_overflow.init.Init
            A shared step for creating the initial state
        """
        task_name = 'default'
        super().__init__(component=component, name=task_name, indir=indir)

        self.add_step(init, symlink='init')

Adding the Task to the Component

Update your add_my_overflow_tasks() function in polaris/tasks/ocean/my_overflow/__init__.py to create and add the Default task for each supported resolution, similar to how it is done in overflow:

from polaris.config import PolarisConfigParser as PolarisConfigParser
from polaris.tasks.ocean.my_overflow.default import Default as Default
from polaris.tasks.ocean.my_overflow.init import Init as Init


def add_my_overflow_tasks(component):
    """
    Add a task following the "my overflow" test case of Petersen et al. (2015)
    doi:10.1016/j.ocemod.2014.12.004

    component : polaris.ocean.Ocean
        the ocean component that the task will be added to
    """
    indir = 'planar/my_overflow'
    config_filename = 'my_overflow.cfg'
    config = PolarisConfigParser(filepath=f'{indir}/{config_filename}')
    config.add_from_package('polaris.tasks.ocean.my_overflow', config_filename)

    init_step = Init(component=component, name='init', indir=indir)
    init_step.set_shared_config(config, link=config_filename)

    default = Default(component=component, indir=indir, init=init_step)
    default.set_shared_config(config, link=config_filename)
    component.add_task(default)

← Back to Adding a Shared Step

→ Continue to Testing the First Task and Step

Adding a First Task

Adding a default Task

Adding the Task to the Component

Adding a `default` Task