Using Links

Download: example_14_links.py

You can also link between different nodes of your Trajectory:

import os  # To allow file paths working under Windows and Linux

from pypet import Environment, Parameter


def multiply(traj):
    """Example of a sophisticated simulation that involves multiplying two values.

    :param traj:

        Trajectory containing
        the parameters in a particular combination,
        it also serves as a container for results.

    """
    z = traj.mylink1 * traj.mylink2  # And again we now can also use the different names
    # due to the creation of links
    traj.f_add_result("runs.$.z", z, comment="Result of our simulation!")


# Create an environment that handles running
filename = os.path.join("hdf5", "example_14.hdf5")
env = Environment(
    trajectory="Multiplication",
    filename=filename,
    file_title="Example_14_Links",
    overwrite_file=True,
    comment="How to use links",
)

# The environment has created a trajectory container for us
traj = env.trajectory

# Add both parameters
traj.par.x = Parameter("x", 1, "I am the first dimension!")
traj.par.y = Parameter("y", 1, "I am the second dimension!")

# Explore just two points
traj.f_explore({"x": [3, 4]})

# So far everything was as in the first example. However now we add links:
traj.f_add_link("mylink1", traj.f_get("x"))
# Note the `f_get` here to ensure to get the parameter instance, not the value 1
# This allows us now to access x differently:
print("x=" + str(traj.mylink1))
# We can try to avoid fast access as well, and recover the original parameter
print(str(traj.f_get("mylink1")))
# And also colon notation is allowed that creates new groups on the fly
traj.f_add_link("parameters.mynewgroup.mylink2", traj.f_get("y"))


# And, of course, we can also use the links during run:
env.run(multiply)

# Finally disable logging and close all log-files
env.disable_logging()