# ggtree

> R package for visualization and annotation of phylogenetic trees with their covariates and other associated data

**Wikidata**: [Q112338735](https://www.wikidata.org/wiki/Q112338735)  
**Source**: https://4ort.xyz/entity/ggtree

## Summary
**ggtree** is a software package designed for the R programming language to visualize and annotate phylogenetic trees. It enables users to integrate tree structures with associated data, such as covariates, for comprehensive analysis. The package is maintained by Guangchuang Yu and is part of the Bioconductor project.

## Key Facts
*   **Category:** It is an instance of software, specifically an R package and a project within the Bioconductor ecosystem.
*   **Primary Function:** Visualization and annotation of phylogenetic trees with covariates and other associated data.
*   **Maintainer:** Guangchuang Yu.
*   **License:** Distributed under the Artistic License 2.0.
*   **Programming Language:** Written in R (a programming language for statistical analysis).
*   **Source Code:** Hosted on GitHub at `https://github.com/YuLab-SMU/ggtree`.
*   **Website:** Official documentation and information located at `https://yulab-smu.top/contribution-tree-data/`.
*   **Copyright Status:** Copyrighted.

## FAQs
### Q: What is ggtree used for?
A: ggtree is used for the visualization and annotation of phylogenetic trees. It allows researchers to display evolutionary relationships and connect them with external data, such as covariates and other associated metadata.

### Q: Who maintains the ggtree package?
A: The software is maintained by Guangchuang Yu.

### Q: Is ggtree free to use?
A: Yes, ggtree is open-source software distributed under the Artistic License 2.0.

### Q: Where can the source code be found?
A: The source code repository is available on GitHub at `https://github.com/YuLab-SMU/ggtree`.

## Why It Matters
ggtree plays a critical role in bioinformatics by bridging the gap between complex evolutionary data and statistical visualization. Phylogenetic trees are fundamental to understanding evolutionary relationships, but raw tree structures often lack the context provided by experimental metadata. ggtree solves this problem by providing a specialized tool within the R environment to annotate trees with "covariates and other associated data."

By operating as part of the Bioconductor project, it integrates seamlessly into standard pipelines for statistical analysis and genomic data science. This allows biologists and data scientists to programmatically generate publication-ready figures that combine hierarchical tree structures with rich, layered datasets, facilitating a deeper understanding of the biological traits associated with evolutionary history. Its open-source nature under the Artistic License 2.0 ensures it is accessible for both academic and commercial research applications.

## Notable For
*   **Visualization and Annotation:** Specifically designed to handle not just tree structures, but the visualization of associated covariates and metadata alongside them.
*   **R Ecosystem Integration:** Functions as a dedicated R package, allowing it to leverage the statistical capabilities of the R programming language.
*   **Bioconductor Project:** It is a recognized package within the Bioconductor project, a standard repository for bioinformatics software.
*   **Open Source Accessibility:** Utilizes the Artistic License 2.0, facilitating broad usage and modification.

## Body
### Software Classification
ggtree is classified as a non-tangible executable component of a computer system (software) and is specifically categorized as an R package and a Bioconductor project. It is built using the R programming language, which was established in 1993 for statistical analysis.

### Functionality and Features
The primary utility of ggtree is the visualization and annotation of phylogenetic trees. Unlike basic tree viewers, ggtree emphasizes the integration of "covariates and other associated data." This allows users to map external data onto the nodes and branches of a tree, providing a visual representation of how different variables correlate with evolutionary divergence.

### Development and Repository
The project is actively maintained by Guangchuang Yu. The codebase is stored in a public Git repository hosted by GitHub. The repository identifier is `YuLab-SMU/ggtree`, indicating its affiliation with the Yu Lab at Southern Medical University (implied by the URL structure, though the raw data only specifies YuLab-SMU). The project has an active website provided by the maintainers for documentation and user support.

### Licensing and Legal
The software is copyrighted and licensed under the terms of the Artistic License 2.0. This license permits the use, modification, and distribution of the software, provided the terms of the Artistic License are met. The license status was verified and referenced via Bioconductor documentation.

## References

1. [Source](https://doi.org/10.18129/b9.bioc.ggtree)
2. [Source](https://api.github.com/repos/YuLab-SMU/ggtree)