10. Documentation

10.1. Viewing METplus documentation

The METplus documentation (beginning with version 3.0) is available online.

10.2. Doxygen Source Code Documentation

The source code documentation is coming soon.

10.3. Documentation Overview

The majority of the documentation is created using the Sphinx documentation generator tool, which was originally created for Python documentation. The documentation is created using reStructuredText (rst).

The following Sphinx modules are required to generate the necessary documentation:

  • sphinx-2.2.0

  • sphinx-gallery-0.7

  • sphinx_rtd_theme-0.4.3

Which versions are being used by the current METplus release can be viewed by looking at either environment.yml or requirements.txt, both of which are found in the METplus/ directory. If the desire is to replicate all the packages employed by METplus, please refer to Section 4 of the Contributor’s Guide.

10.4. Description of Documentation Directories

Core documentation is divided into four sections: User’s Guide, Contributor’s Guide, Release Guide, and Verification Datasets Guide all of which reside under the METplus/docs directory and contain files ending in .rst.

Documentation for the use cases is found in the following directories:

  • METplus/docs/use_cases/met_tool_wrapper

    • This directory contains documentation pertaining to use cases that use one MET tool/METplus wrapper.

  • METplus/docs/use_cases/model_applications

    • This directory contains documentation pertaining to use cases that are based on model data, and utilize more than one MET tool/METplus wrapper.

Please refer to the Document New Use Case section for more information on documenting a new use case.

10.5. Adding New Documentation

To determine where to add new documentation:

  • The User’s Guide for any instructions or details that will enable a user to run/use the use case and/or new code.

  • The Contributor’s Guide for instructions on creating/constructing new code.

  • The Release Guide for instructions for creating software releases for any METplus component, including official, bugfix, and development releases.

  • The Verification Datasets Guide for any relevant “truth” datasets, including data from satellite platforms (geostationary and polar orbiting), gridded analyses (global and regional), station or point-based datasets (global and regional), and radar networks.

10.5.1. User’s Guide:

  • To add/modify any content that affects METplus users.

  • Modify any of the affected sections from the METplus/docs/Users_Guide directory:

    • glossary.rst (Glossary)

    • references.rst (Reference)

    • configuration.rst (Configuration)

    • usecases.rst (Use cases)

    • wrappers.rst (METplus wrappers)

10.5.2. Contributor’s Guide:

  • To add/modify any content that affects METplus contributors.

  • Modify any of the affected sections from the METplus/docs/Contributors_Guide directory:

    • add_use_case.rst (How to add new use cases)

    • basic_components.rst (The basic components of a METplus wrapper)

    • coding_standards.rst (The coding standards currently in use)

    • conda_env.rst (How to set up the conda environment for running METplus)

    • continuous_integration.rst (How to set up a continuous integration workflow)

    • create_wrapper.rst (How to create a new METplus wrapper)

    • deprecation.rst (What to do to deprecate a variable)

    • documentation.rst (Describing the documentation process and files)

    • github_workflow.rst (A description of how releases are made, how to to obtain source code from the GitHub repository)

    • index.rst (The page that shows all the ‘chapters/sections’ of the Contributor’s Guide)

    • testing.rst (A description of how to set up testing the wrapper code)

10.5.3. Release Guide:

  • To add/modify the instructions for creating software releases for any METplus component, including official, bugfix, and development releases.

  • Each METplus component has a top level file (e.g. metplus.rst) which simply contains references to files for each of the releases. For example, metplus.rst contains references to:

    • metplus_official.

    • metplus_bugfix.

    • metplus_development.

  • Each release file (e.g. metplus_official.rst, metplus_bugfix.rst, metplus_development.rst) contains, at a minimum, a replacement value for the projectRepo variable and include statements for each release step. These individual steps (e.g. open_release_issue.rst, clone_project_repository.rst, etc.) may be common to multiple METplus components. These common steps are located in the release_steps directory. However, a METplus component may have different instructions from other components (e.g. For METplus wrappers, update_version.rst, create_release_extra.rst, etc.). In this case, the instructions that are specific to that component are located in a subdirectory of release_steps. For example, files that are specific to METplus wrappers are located in release_steps/metplus, files that are specific to METcalcpy are located in release_steps/metcalcpy.

  • The file for each individual step (e.g. open_release_issue.rst, update_version.rst, etc.) contains the instructions for completing that step for the release.

10.5.4. Verification Datasets Guide:

  • To add/modify any relevant datasets in an attempt to create a centralized catalog of verification datasets to provide the model verification community with relevant “truth” datasets. See the Verification Datasets Guide Overview for more information.

10.6. Read the Docs METplus Documentation

The METplus components use Read the Docs to build and display the documentation. Read the Docs simplifies the documentation process by building, versioning, and hosting the documentation.

Read the Docs supports multiple versions for each repository. For the METplus components, the “latest” version will point to the latest official (stable) release. The “develop” or “development” version will point to the most up to date development code. There may also be other previous versions of the software available in the version selector menu, which is accessible by clicking in the bottom left corner of the documentation pages.

Automation rules allow project maintainers to automate actions on new branches and tags on repositories. For the METplus components, documentation is automatically built by Read the Docs when a new tag is created and when a branch is created with the prefix:

  • feature (e.g. feature_836_rtd_doc)

  • bugfix (e.g. bugfix_1716_develop_perc_thresh)

The documentation of these “versions” are automatically hidden, however, the documentation can be accessed by directly modifying the URL. For example, to view “feature_836_rtd_doc” for the METplus repository the URL would be:


(Note that this link is not valid as this branch does not currently exist, however contributors can replace the “feature_836_rtd_doc” with the appropriate branch name.)

The URL branch name will be lowercase regardless of the actual branch letter casing, i.e. “feature_836_RTD_Doc” branch would be accessed by the above-mentioned URL.

Read the Docs will automatically delete the documentation for a feature branch and a bugfix branch when the branch is deleted.

Documentation for each METplus component can be found at the links below:

10.7. Building Sphinx Documentation Manually

Documentation does not have to be built manually as it is automatically generated by Read The Docs. See the Read the Docs section for further information. However, contributors can still build the documentation manually if desired.


It is assumed that the web browser application and METplus source code are located on the same computer/host.

All the sphinx modules (listed earlier) need to be present in order to generate the HTML content that comprises the documentation. From the command line, change to the METplus/docs directory and enter the following:


This script does the following:

  • Builds the Sphinx documentation

  • Builds the doxygen documentation

  • Removes unwanted text from use case documentation

  • Copies doxygen files into* _build/html* for easy deployment

  • Creates symbolic links under Users_Guide to the directories under ‘generated’ to preserve old URL paths

The html files that are created can be found in the METplus/docs/_build/html directory. The web browser can point to this directory by entering the following in the web browser’s navigation bar:


Where <path-to> is the full file path leading to the METplus source code. This will direct to the home page of the documentation. Click on the links to navigate to the desired information.

10.8. Relevant Documentation for Contributors

The Doxygen tool is employed to create documentation from the source code. This documentation is useful in generating details about the METplus wrapper API (Application Programming Interface). This is a useful reference for contributors to peruse prior to creating new METplus wrappers. The Doxygen files located in the /path/to/METplus/docs/doxygen directory do NOT need to be modified and should not be modified.

For more information about Doxygen, please refer to this Doxygen web page.

Download and install Doxygen to create this documentation.

Note: Doxygen version or higher is required to create the documentation for the METplus wrappers.

Create the Doxygen documentation by performing the following:

  • Ensure that the user is working with Python 3.6 (minimum).

  • cd to the /path/to/METplus/sorc directory, where /path/to is the file path where the METplus source code is installed.

  • At the command line, enter the following:

    make clean
    make doc

The first command cleans up any existing documentation, and the second generates new documentation based on the current source code.

The HTML files are generated in the /path/to/METplus/docs/doxygen/html directory, which can be viewed in the local browser. The file corresponding to the home page is /path/to/METplus/docs/doxygen/html/index.html.

Useful information can be found under the Packages, Classes, and Python Files tabs located at the top of the home page.