ggchord - Layered Chord, Circular and Linear Sequence Visualization

A 'ggplot2'-based package for multi-sequence alignment chord diagrams, linear collinearity plots and single circular sequence maps. A layered grammar combines sequence backbones, interval links, genes, general biological features, labels, quantitative tracks, genomic axes and restriction sites. Feature placement is expressed with reusable Position objects, while role-specific scales and themes keep data mapping separate from geometry and appearance.