Building an Extensible, rEproducible, Test-driven, Harmonized, Open-source, Versioned, ENsemble model for air quality

beethoven is a targets reproducible analysis pipeline with the following workflow.

Version 0.4.4 of beethoven has stable targets for downloading data files, calculating features at AQS sites, and merging to a base learner-ready data.table (dt_feat_calc_xyt). Ongoing changes relate to calculating features for the prediction grid, computationally managing prediction grid, base learner hyperparameter tuning, and meta learner function development.

r targets::tar_visnetwork()

Organization

Here, we describe the structure of the repository, important files, and the targets object naming conventions.

Folder Structure

• R/ is where the beethoven functions are stored. Only ".R" files should be in this folder (ie. targets helpers, post-processing, model fitting functions).
• inst/ is a directory for arbitrary files outside of the main R/ directory
  • targets/ is a sub-directory within inst/ which contains the pipeline files (ie. "targetsaqs.R"). These files declare the `targets::tartargetobjects which constitute thebeethoven` pipeline.
• tests/ stores unit and integration tests (testthat/) and test data (testdata/) according to the testthat package's standard structure. for unit testing.
  • testthat.R is created and maintained by testthat, and is not to be edited manually.
• container/ stores definition files and build scripts to build covariate- and model-specific Apptainer container images (container_covariates.def and container_models.def).
• man/ contains function documentation files (".Rd") which are by the roxygen2 package. These files are not to be edited manually.
• vignettes/ contains ".Rmd" narrative text and code files. These are rendered by pkgdown into the Articles section of the beethoven webpage.
• .github/workflows/ is a hidden directory which stores the GitHub CI/CD "yaml" files.
• tools/ is dedicated to educational or demonstration material (e.g. Rshiny), but is not excluded from the package build.

Important Files

• _targets.R configures targets settings, creates computational resource controllers, and structures the beethoven pipeline.
  • To run beethoven, users must review and update the following parameters for their user profile and computing system:
  • controller_* Ensure the local controllers do not request more CPUs than are available on your machine or high performance system.
  • #SBATCH --partition Utilization of NVIDIA GPUs (within glue::glue command)
  • --bind /USER_PATH_TO_INPUT/input:/input (within glue::glue command)
• _targets.yaml is created and updated by running targets::tar_make and is not to be edited manually.
• run.sh submits separate SBATCH jobs for the covariate, cpu- and gpu-enabled base learner, and the meta learner targets (see /inst/scripts/). This setup ensures that each stage utilizes the proper container image and computational resources. To run beethoven, users must review and update the following parameters for their user profile and computing system in each of the inst/scripts/run_* files.:
  • #SBATCH --mail-user
  • #SBATCH --partition
  • #SBATCH --mem
  • #SBATCH --cpus-per-task
  • --bind /USER_PATH_TO_INPUT/input:/input
  • --bind /USER_PATH_TO_SLURM/slurm:/USER_PATH_TO_SLURM/slurm

Running beethoven Pipeline

User settings

beethoven pipeline is configured for SLURM with defaults for NIEHS HPC settings. For adapting the settings to users' environment, consult with the documentation of your platform and edit the requested resources in the stage-specific run files (/inst/scripts/) (lines 3-11) and _targets.R (lines 41-45; individual crew and crew.cluster controller workers).

Critical targets

There are 5 "critical" targets that users may want to change to run beethoven.

• chr_daterange
  • Controls all time-related targets for the entire pipeline. This is the only target that needs to be changed to update the pipeline with a new temopral range. Month and year specific arguments are derived from the time range defined by chr_daterange.
• chr_nasa_token
  • Sets the file path to the user's NASA Earthdata account credentials. These credentials expire at ~90 day intervals and therefore must be updated regularly.
• chr_mod06_links
  • The file path to the MOD06 links file. These links must be manually downloaded per the amadeus::download_modis function. The links are then stored in a CSV file that is read by the function. The new file with links must be updated to match the new date range.
• chr_input_dir
  • The file path to the input directory. This target controls where the raw data files are downloaded to and imported from. This file path must be mounted to the container at run time in the run.sh script.
• num_dates_split
  • Controls the size of temporal splits. Splitting the temporal range into smaller chunks allows for parallel processing across multiple workers. It also allows for dispatching new dynamic branches when the temporal range is updated.

Apptainer

Current implementation of beethoven utilizes Apptainer images to run the pipeline with consistent package versions and custom installations. Users must build these images before runnning beethoven.

sh cd container/ # must be working in the `container/` directory sh build_container_covariates.sh # build "covariates" stage image sh build_container_models.sh # build "models" image mv *sif ../ # move images to `beethoven/` root directory

[!NOTE] .sif files are omitted from GitHub due to size (>5 Gb each)

Run

After switching back to the project root directory, users can run the pipeline with the run.sh shell script. The following lines of /inst/scripts/run_*.sh must be updated with user-specific settings before running the pipeline

```sh

SBATCH --mail-user=[USER_EMAIL] # email address for job notifications

SBATCH --partition=[PARTITION_NAME] # HPC partition to run on

SBATCH --mem=[###G] # Total memory for the job

SBATCH --cpus-per-task=[###] # Total CPUs for the job

... --bind [USERINPUTDIRECTORY]/input:/input \ ... --bind [USERSYSTEMPATH/munge]:/run/munge \ --bind [USERSYSTEMPATH/slurm]:[USERSYSTEMPATH/slurm] \ ```

Once configured, the pipeline can be run with a SLRUM batch job.

sh cd ../ # assuming still in the `container/` directory sbatch run.sh

The SLURM batch job can also be submitted R session with the batch helper function.

r source("R/helpers.R") batch()

Contribution

The Developer's Guide provides detailed instructions for how to develop or update beethoven settings or individual targets objecdts

To contribute developments or modifications, open a Pull request into the dev branch with a detailed description of the proposed changes. Pull requests must pass all status checks, and then will be approved or rejected by beethoven's authors.

Utilize Issues to notify the authors of bugs, questions, or recommendations. Identify each issue with the appropriate label to help ensure a timely response.