MROCP

MROCP (the Magnetic Resonance Open Connectome Project, hosted at Johns Hopkins University under the awesome.cs.jhu.edu "graph-services" umbrella) is a web-based suite of tools for working with brain-connectivity graphs, and its "Graph conversion" endpoint is a general-purpose format converter for network files. The project grew out of Johns Hopkins connectomics research and is closely tied to the NeuroData m2g / MR-OCP pipeline, which turns structural and diffusion MRI scans into multi-resolution connectomes. A connectome in this context is a weighted, typically undirected graph whose nodes are anatomically defined brain regions (from a chosen parcellation atlas) and whose edge weights count reconstructed white-matter fiber tracts between region pairs; the pipeline's native output is an edge list, and MROCP's default distribution format is format:graphml, chosen because it is the only supported format that can carry the iterable node/edge attributes connectomes require.

The conversion service itself is broader than neuroscience. It accepts a graph and re-emits it in a target format, spanning GraphML, format:ncol, plain edge lists (format:edge-list), LGL, format:pajek, a "graphdb" binary form, format:dot, format:gml, format:leda, NumPy .npy arrays, MATLAB .mat matrices, and an "attredge" attributed-edge-list variant. The dense-matrix targets (.npy, .mat) reflect its origin: connectomes are naturally handled as adjacency matrices for graph-theoretic and statistical analysis. The heavy lifting is done by the tool:igraph library, which MROCP also exposes through companion pages of igraph usage examples alongside invariant-computation and download services.

Because it wraps igraph, MROCP-convert inherits that library's format coverage and its data model, making it a lightweight, browser-accessible alternative to running local scripts for one-off translations between matrix-oriented (format:matrix-market-style) and graph-oriented representations. Related general-purpose converters in the same niche include tool:networkx and tool:graph-tool for programmatic conversion.

Its limitations follow from its research provenance. MROCP is an academic web service, not a maintained commercial product; availability and uptime can be intermittent, and it targets simple node/edge/weight graphs rather than richly typed property graphs or semantic formats. Attribute handling outside GraphML is limited, and the tool is best understood as a convenience layer over igraph for connectome-style networks rather than a comprehensive interchange engine.