Circos Collinearity Chord Diagram

Free online Circos collinearity chord diagram generator. Upload a seven-column CSV in the form source_group,source_start,source_end,target_group,target_start,target_end,color and the tool turns ring segments into continuous one-dimensional tracks with coordinate ticks. Thin curves in the middle encode interval-to-interval mapping or synteny correspondence. A default sample is included and you can export PNG / SVG immediately.

What this chart is

An ordinary chord diagram treats each node as a discrete category and each connection as weighted flow. A Circos collinearity plot is different: every ring segment is a continuous track with its own position scale, so the picture is not “node A to node B”, but “interval on track A maps to interval on track B”. That is why this layout is useful for genome synteny, storage block migration, address-range remapping, order-batch reassignment, stratigraphic alignment and similar problems. Crossings are not noise here — they are the visual expression of permutation, rearrangement, remap or displacement.

What you can do

• Upload interval-mapping CSV rows.
• Automatically render continuous tracks, sparse coordinate ticks, thin mapping curves and right-side leader labels for dense short targets.
• Download a template that matches the default sample exactly.
• Switch light / dark mode without changing the layout logic.
• Export clean PNG / SVG.
• Keep all processing local in the browser.

How to use it

1. Open the page and inspect the built-in sample, which mimics upper AtChr.* tracks mapped to right-lower Sca.* / ApChr.* tracks.
2. Upload your own CSV. Each row describes one interval mapping, not a simple discrete source,target,value relationship.
3. Hover curves or tracks to inspect track names and interval ranges.
4. Export PNG or SVG when the layout looks right.

Example:

source_group,source_start,source_end,target_group,target_start,target_end,color
AtChr.1,2,9,Sca.186,1,4,purple
AtChr.2,9,16,ApChr.12,4,10,red
AtChr.4,11,18,ApChr.1,4,13,purple

Where it fits

• Genome collinearity and synteny
• Storage block migration or rebalance
• NAT / route remapping by address ranges
• Static-to-runtime memory relocation
• Batch reassignment in supply chains
• Depth, time or energy interval correspondence in science

Notes

This tool is about interval mapping on continuous coordinates, not category-to-category traffic totals. If your question is simply “how much flows from A to B”, a regular chord diagram is usually the better fit. The current template keeps source tracks on the upper arc and target tracks on the right-lower arc, with Sca.*-style short targets using leader labels to stay readable and to match the uploaded reference image closely.

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Last verified: 2026-09-11

How to read it

Start with the outer ring: each segment is a continuous track, and the 0 / 10 / 20 / 30 labels are position ticks, not category IDs. Then read the center curves: every curve means “this interval on the source track corresponds to that interval on the target track”. Heavy crossing suggests permutation, rearrangement or remap; mostly parallel curves suggest better order preservation. The right-side Sca.* labels use leader lines because those tracks are short and dense.