Lab Command

🚀 The Lab Command

Before running anything in SLM Lab, be sure to activate the Conda environment:

conda activate lab

In SLM Lab, everything is run with the lab command with the following form:

python run_lab.py {spec file} {spec name} {lab mode}

This command runs any algorithm/environment specified in a spec file in SLM Lab. Spec files are located in the slm_lab/spec/ folder.

The Spec File

The spec file contains the spec – a set of fully exposed hyperparameters that configure a run, including the agent, environment, and hyperparameter search. The spec name refers to a specific spec in the spec file.

All the spec files are defined in the slm_lab/spec/ folder. The spec file has the following format:

{
  "{spec name}": {
    "agent": [{...}],
    "env": [{...}],
    ...
    "search": [{...}]
  },
  "{spec name 2}": {
    ...
  },
  ...
}

The Lab Modes

We will take a deep dive into the spec file in the coming sections, since it is crucial to running SLM Lab. Next, the lab mode specifies one of the modes used to run the lab:

• dev: for development with verbose logging, environment rendering, and helpful checks like gradient updates. This is slower but useful for development.

• train: for training an agent to completion. This disables the development helper tools and thus runs the fastest.

• train@{predir}: for resuming training, e.g. train@latest will use the latest run for a spec, and train@data/reinforce_cartpole_2020_04_13_232521 will use the specified run.

• enjoy@{session_spec_file}: for replaying a trained model from a trial-session; session_spec_file specifies the spec file from a session, e.g. enjoy@data/reinforce_cartpole_2020_04_13_232521/reinforce_cartpole_t0_s0_spec.json.

• search: for running an experiment / hyperparameter search.

In Quick Start, we used the lab command to read the demo spec file at slm_lab/spec/demo.json, use the dqn_cartpole spec in it, and run the spec in dev mode. To rerun the demo in train mode, we can simply change the lab mode to train to get the following:

python run_lab.py slm_lab/spec/demo.json dqn_cartpole train

In the coming sections we will learn to use SLM Lab with more hands-on tutorials.