A modern Shiny GUI for graphical multiple comparison procedures
alphagraph is a Shiny-based graphical user interface for designing, visualizing, and analyzing graphical multiple comparison procedures (gMCPs) as implemented in the R package graphicalMCP.
The project aims to provide a modern, interactive, and maintainable alternative to the Java-based GUI of the gMCP package while remaining fully compatible with R-based workflows and future extensions such as group sequential designs (GSDs).
Motivation
Graphical multiple comparison procedures are widely used in confirmatory clinical trials to control the familywise error rate (FWER) while allowing flexible allocation and reallocation of significance levels across multiple hypotheses.
The existing gMCP package provides a powerful GUI, but its Java-based architecture presents challenges in modern environments:
- Requires a Java installation
- Difficult to deploy in web-based environments
- Harder to maintain and extend
- Less suitable for integration into modern R and Shiny workflows
At the same time, the graphicalMCP package provides a modern and extensible implementation of graphical testing procedures. alphagraph complements this package with an interactive web-based user interface.
Key Features
Interactive Graph Editor
- Create and edit hypotheses (nodes)
- Create and modify transition relationships (edges)
- Drag-and-drop node positioning
- Grid-based layouts
- Interactive node and edge properties
- Zooming and panning
- Validation of graph consistency
Technology Stack
Why visNetwork?
Several technologies were evaluated, including:
igraphggplot2networkD3cytoscape.jsvisNetwork
After a structured evaluation, visNetwork was selected as the preferred graph visualization layer because it provides:
- Excellent Shiny integration
- Bidirectional interaction
- Runtime graph updates
- Interactive graph editing
- Good performance for typical graphical MCP use cases
The underlying graphical testing procedures are represented and analyzed using graphicalMCP and igraph, while visNetwork provides the interactive user interface.
Proof of Concept
A Proof-of-Concept (PoC) application was developed to evaluate the technical feasibility of implementing a Shiny-based graphical MCP editor.
The PoC demonstrated that:
- The look and feel of the original
gMCPGUI can be closely approximated. - Interactive graph editing is feasible using modern web technologies.
- User requirements identified from the existing
gMCPGUI can be implemented without relying on Java.
The PoC focuses on validating technical concepts and user experience and does not yet implement the complete functionality planned for the final application.
Relationship to graphicalMCP
alphagraph is intended to serve as a graphical front-end for graphicalMCP.
The long-term architecture separates responsibilities:
| Component | Responsibility |
|---|---|
graphicalMCP |
Statistical methods, graph representation, validation, analysis |
alphagraph |
Interactive graph editing and visualization |
Future export package (e.g. alphagraphTikZ) |
Publication-ready TikZ/LaTeX export |
This separation allows statistical functionality to remain available in pure R workflows while providing a modern graphical user interface for interactive use.
Future Directions
Planned future developments include:
- Support for group sequential designs
- Advanced graph editing features
- Interactive analysis workflows
- Report generation
- TikZ/LaTeX export
- Integration into RPACT Cloud
Status
⚠️ Early development
alphagraph is currently under active development. APIs, functionality, and user interfaces may change substantially before the first public release.
Acknowledgements
The development of alphagraph is inspired by the graphical testing framework developed by Frank Bretz and colleagues and the existing gMCP and graphicalMCP packages.
Special thanks to the graphicalMCP development team for ongoing discussions and collaboration.