import * as PERMUTE from './permute.js'; import * as CELLINDEX from './cellindex.js'; function index_nodes(nodes, scale) { let i = 1; for( const n of nodes ) { n["id"] = i; i++; } } function scale_nodes(nodes, scale) { for( const n of nodes ) { for( const a of [ 'x', 'y', 'z', 'w' ] ) { n[a] = scale * n[a]; } } } function dist2(n1, n2) { return (n1.x - n2.x) ** 2 + (n1.y - n2.y) ** 2 + (n1.z - n2.z) ** 2 + (n1.w - n2.w) ** 2; } export function auto_detect_edges(nodes, neighbours, debug=false) { const seen = {}; const nnodes = nodes.length; const links = []; let id = 1; for( const n1 of nodes ) { const d2 = []; for( const n2 of nodes ) { d2.push({ d2: dist2(n1, n2), id: n2.id }); } d2.sort((a, b) => a.d2 - b.d2); const closest = d2.slice(1, neighbours + 1); if( debug ) { console.log(`closest = ${closest.length}`); console.log(closest); } for( const e of closest ) { const ids = [ n1.id, e.id ]; ids.sort(); const fp = ids.join(','); if( !seen[fp] ) { seen[fp] = true; links.push({ id: id, label: 0, source: n1.id, target: e.id }); id++; } } } if( debug ) { console.log(`Found ${links.length} edges`) } return links; } // too small and simple to calculate export const cell5 = () => { const r5 = Math.sqrt(5); const r2 = Math.sqrt(2) / 2; return { name: '5-cell', nodes: [ {id:1, label: 1, x: r2, y: r2, z: r2, w: -r2 / r5 }, {id:2, label: 2, x: r2, y: -r2, z: -r2, w: -r2 / r5 }, {id:3, label: 3, x: -r2, y: r2, z: -r2, w: -r2 / r5 }, {id:4, label: 4, x: -r2, y: -r2, z: r2, w: -r2 / r5 }, {id:5, label: 5, x: 0, y: 0, z: 0, w: 4 * r2 / r5 }, ], links: [ { id:1, source:1, target: 2}, { id:2, source:1, target: 3}, { id:3, source:1, target: 4}, { id:4, source:1, target: 5}, { id:5, source:2, target: 3}, { id:6, source:2, target: 4}, { id:7, source:2, target: 5}, { id:8, source:3, target: 4}, { id:9, source:3, target: 5}, { id:10, source:4, target: 5}, ], geometry: { node_size: 0.02, link_size: 0.02 }, options: [ { name: '--' }] }; }; export const cell16 = () => { let nodes = PERMUTE.coordinates([1, 1, 1, 1], 0); nodes = nodes.filter((n) => n.x * n.y * n.z * n.w > 0); nodes[0].label = 1; nodes[3].label = 2; nodes[5].label = 3; nodes[6].label = 4; nodes[7].label = 1; nodes[4].label = 2; nodes[2].label = 3; nodes[1].label = 4; index_nodes(nodes); scale_nodes(nodes, 0.75); const links = auto_detect_edges(nodes, 6); return { name: '16-cell', nodes: nodes, links: links, geometry: { node_size: 0.02, link_size: 0.02 }, options: [ { name: '--' }] }; }; export const tesseract = () => { const nodes = PERMUTE.coordinates([1, 1, 1, 1], 0); index_nodes(nodes); for( const n of nodes ) { if( n.x * n.y * n.z * n.w > 0 ) { n.label = 2; } else { n.label = 1; } } scale_nodes(nodes, Math.sqrt(2) / 2); const links = auto_detect_edges(nodes, 4); links.map((l) => { l.label = 0 }); for( const p of [ 1, 2 ] ) { const nodes16 = nodes.filter((n) => n.label === p); const links16 = auto_detect_edges(nodes16, 6); links16.map((l) => l.label = p); links.push(...links16); } return { name: 'tesseract', nodes: nodes, links: links, geometry: { node_size: 0.02, link_size: 0.02 }, options: [ { name: 'none', links: [ 0 ] }, { name: 'one 16-cell', links: [ 0, 1 ] }, { name: 'both 16-cells', links: [ 0, 1, 2 ] }, ], }; } const CELL24_INDEXING = { x: { y: 1, z: 3, w: 2 }, y: { z: 2, w: 3 }, z: { w: 1 } }; function node_by_id(nodes, nid) { const ns = nodes.filter((n) => n.id === nid); return ns[0]; } export const cell24 = () => { const nodes = PERMUTE.coordinates([0, 0, 1, 1], 0); for( const n of nodes ) { const axes = ['x', 'y', 'z', 'w'].filter((a) => n[a] !== 0); n.label = CELL24_INDEXING[axes[0]][axes[1]]; } index_nodes(nodes); const links = auto_detect_edges(nodes, 8); links.map((l) => l.label = 0); for( const p of [ 1, 2, 3 ] ) { const nodes16 = nodes.filter((n) => n.label === p); const links16 = auto_detect_edges(nodes16, 6); links16.map((l) => l.label = p); links.push(...links16); } // links.map((l) => { // const ls = [ l.source, l.target ].map((nid) => node_by_id(nodes, nid).label); // for ( const c of [1, 2, 3] ) { // if( ! ls.includes(c) ) { // l.label = c // } // } // }); return { name: '24-cell', nodes: nodes, links: links, geometry: { node_size: 0.02, link_size: 0.02 }, base: {}, options: [ { name: 'none', links: [ 0 ] }, { name: 'one 16-cell', links: [ 0, 1 ] }, { name: 'three 16-cells', links: [ 0, 1, 2, 3 ] } ] }; } // face detection for the 120-cell // NOTE: all of these return node ids, not nodes // return all the links which connect to a node function nodes_links(links, nodeid) { return links.filter((l) => l.source === nodeid || l.target === nodeid); } // filter to remove a link to a given id from a set of links function not_to_this(link, nodeid) { return !(link.source === nodeid || link.target === nodeid); } // given nodes n1, n2, return all neighbours of n2 which are not n1 function unmutuals(links, n1id, n2id) { const nlinks = nodes_links(links, n2id).filter((l) => not_to_this(l, n1id)); return nlinks.map((l) => { if( l.source === n2id ) { return l.target; } else { return l.source; } }) } function fingerprint(ids) { const sids = [...ids]; sids.sort(); return sids.join(','); } function auto_120cell_faces(links) { const faces = []; const seen = {}; let id = 1; for( const edge of links ) { const v1 = edge.source; const v2 = edge.target; const n1 = unmutuals(links, v2, v1); const n2 = unmutuals(links, v1, v2); const shared = []; for( const a of n1 ) { const an = unmutuals(links, v1, a); for( const d of n2 ) { const dn = unmutuals(links, v2, d); for( const x of an ) { for( const y of dn ) { if( x == y ) { shared.push([v1, a, x, d, v2]) } } } } } if( shared.length !== 3 ) { console.log(`Bad shared faces for ${edge.id} ${v1} ${v2}`); } for( const face of shared ) { const fp = fingerprint(face); if( !seen[fp] ) { faces.push({ id: id, nodes: face }); id++; seen[fp] = true; } } } return faces; } export function make_120cell_vertices() { const phi = 0.5 * (1 + Math.sqrt(5)); const r5 = Math.sqrt(5); const phi2 = phi * phi; const phiinv = 1 / phi; const phi2inv = 1 / phi2; const nodes = [ PERMUTE.coordinates([0, 0, 2, 2], 0), PERMUTE.coordinates([1, 1, 1, r5], 0), PERMUTE.coordinates([phi, phi, phi, phi2inv], 0), PERMUTE.coordinates([phiinv, phiinv, phiinv, phi2], 0), PERMUTE.coordinates([phi2, phi2inv, 1, 0], 0, true), PERMUTE.coordinates([r5, phiinv, phi, 0], 0, true), PERMUTE.coordinates([2, 1, phi, phiinv], 0, true), ].flat(); index_nodes(nodes); scale_nodes(nodes, 0.5); return nodes; } function label_nodes(nodes, ids, label) { nodes.filter((n) => ids.includes(n.id)).map((n) => n.label = label); } function label_faces_120cell(nodes, faces, cfaces, label) { const ns = new Set(); for( const fid of cfaces ) { const face = faces.filter((f)=> f.id === fid ); if( face.length > 0 ) { for ( const nid of face[0].nodes ) { ns.add(nid); } } } label_nodes(nodes, Array.from(ns), label); } function link_labels(nodes, link) { const n1 = nodes.filter((n) => n.id === link.source); const n2 = nodes.filter((n) => n.id === link.target); return [ n1[0].label, n2[0].label ]; } // version of the 120-cell where nodes are partitioned by // layer and the links follow that export const cell120_layered = (max) => { const nodes = make_120cell_vertices(); const links = auto_detect_edges(nodes, 4); nodes.map((n) => n.label = 9); // make all invisible by default for (const cstr in CELLINDEX.LAYERS120 ) { label_nodes(nodes, CELLINDEX.LAYERS120[cstr], Number(cstr)); } links.map((l) => { const labels = link_labels(nodes, l); if( labels[0] >= labels[1] ) { l.label = labels[0]; } else { l.label = labels[1]; } }); const options = []; const layers = []; for( const i of [ 0, 1, 2, 3, 4, 5, 6, 7 ] ) { layers.push(i); options.push({ name: CELLINDEX.LAYER_NAMES[i], links: [...layers], nodes: [...layers] }) } return { name: '120-cell layered', nodes: nodes, links: links, geometry: { node_size: 0.02, link_size: 0.02 }, nolink2opacity: true, options: options } } export const cell120_inscribed = () => { const nodes = make_120cell_vertices(); const links = auto_detect_edges(nodes, 4); for( const cstr in CELLINDEX.INDEX120 ) { label_nodes(nodes, CELLINDEX.INDEX120[cstr], Number(cstr)); } links.map((l) => l.label = 0); for( const p of [ 1, 2, 3, 4, 5 ]) { const nodes600 = nodes.filter((n) => n.label === p); const links600 = auto_detect_edges(nodes600, 12); links600.map((l) => l.label = p); links.push(...links600); } return { name: '120-cell', nodes: nodes, links: links, geometry: { node_size: 0.02, link_size: 0.02 }, options: [ { name: "none", links: [ 0 ]}, { name: "one inscribed 600-cell", links: [ 0, 1 ] }, { name: "five inscribed 600-cells", links: [ 0, 1, 2, 3, 4, 5 ] } ] } } function partition_coord(i, coords, invert) { const j = invert ? -i : i; if( j >= 0 ) { return coords[j]; } return "-" + coords[-j]; } function partition_fingerprint(n, coords, invert) { const p = ['x','y','z','w'].map((a) => partition_coord(n[a], coords, invert)); const fp = p.join(','); return fp; } function label_vertex(n, coords, partition) { const fp = partition_fingerprint(n, coords, false); if( fp in partition ) { return partition[fp]; } else { const ifp = partition_fingerprint(n, coords, true); if( ifp in partition ) { return partition[ifp]; } console.log(`Map for ${fp} ${ifp} not found`); return 0; } } function map_coord(i, coords, values) { if( i >= 0 ) { return values[coords[i]]; } return -values[coords[-i]]; } export function make_600cell_vertices() { const coords = { 0: '0', 1: '1', 2: '2', 3: 't', 4: 'k' }; const t = 0.5 * (1 + Math.sqrt(5)); const values = { '0': 0, '1': 1, '2': 2, 't': t, 'k': 1 / t }; const nodes = [ PERMUTE.coordinates([0, 0, 0, 2], 0), PERMUTE.coordinates([1, 1, 1, 1], 0), PERMUTE.coordinates([3, 1, 4, 0], 0, true) ].flat(); for( const n of nodes ) { n.label = label_vertex(n, coords, CELLINDEX.PARTITION600); } for( const n of nodes ) { for( const a of [ 'x', 'y', 'z', 'w'] ) { n[a] = map_coord(n[a], coords, values); } } index_nodes(nodes); scale_nodes(nodes, 0.75); return nodes; } function get_node(nodes, id) { const ns = nodes.filter((n) => n.id === id); if( ns ) { return ns[0] } else { return undefined; } } function audit_link_labels(nodes, links) { for( const l of links ) { const n1 = get_node(nodes, l.source); const n2 = get_node(nodes, l.target); if( n1.label === n2.label ) { console.log(`link ${l.id} joins ${n1.id} ${n2.id} with label ${n2.label}`); } } } export const cell600 = () => { const nodes = make_600cell_vertices(); const links = auto_detect_edges(nodes, 12); links.map((l) => l.label = 0); for( const p of [1, 2, 3, 4, 5]) { const nodes24 = nodes.filter((n) => n.label === p); const links24 = auto_detect_edges(nodes24, 8); links24.map((l) => l.label = p); links.push(...links24); } return { name: '600-cell', nodes: nodes, links: links, geometry: { node_size: 0.02, link_size: 0.02 }, options: [ { name: "none", links: [ 0 ]}, { name: "one 24-cell", links: [ 0, 1 ] }, { name: "five 24-cells", links: [ 0, 1, 2, 3, 4, 5 ] } ] } } export const cell600_layered = () => { const nodes = make_600cell_vertices(); const links = auto_detect_edges(nodes, 12); nodes.map((n) => n.label = 9); // make all invisible by default for (const cstr in CELLINDEX.LAYERS600 ) { label_nodes(nodes, CELLINDEX.LAYERS600[cstr], Number(cstr)); } links.map((l) => { const labels = link_labels(nodes, l); if( labels[0] >= labels[1] ) { l.label = labels[0]; } else { l.label = labels[1]; } }); const options = []; const layers = []; for( const i of [ 0, 1, 2, 3, 4, 5, 6, 7 ] ) { layers.push(i); options.push({ name: CELLINDEX.LAYER_NAMES[i], links: [...layers], nodes: [...layers] }) } return { name: '600-cell layered', nodes: nodes, links: links, geometry: { node_size: 0.02, link_size: 0.02 }, nolink2opacity: true, options: options } } export const snub24cell = () => { const nodes600 = make_600cell_vertices(); const links600 = auto_detect_edges(nodes600, 12); const nodes = nodes600.filter((n) => n.label != 1); const links = links600.filter((l) => { const sn = node_by_id(nodes, l.source); const tn = node_by_id(nodes, l.target); return sn && tn; }); links.map((l) => l.label = 0); return { name: 'snub 24-cell', nodes: nodes, links: links, geometry: { node_size: 0.02, link_size: 0.02 }, options: [ { name: "--" } ], } } function make_dodecahedron_vertices() { const phi = 0.5 * (1 + Math.sqrt(5)); const phiinv = 1 / phi; const nodes = [ { x: 1, y: 1, z: 1, w: 0, label: 4 }, { x: 1, y: 1, z: -1, w: 0, label: 3 }, { x: 1, y: -1, z: 1, w: 0, label: 3 }, { x: 1, y: -1, z: -1, w: 0, label: 2 }, { x: -1, y: 1, z: 1, w: 0, label: 3 }, { x: -1, y: 1, z: -1, w: 0, label: 1 }, { x: -1, y: -1, z: 1, w: 0, label: 5 }, { x: -1, y: -1, z: -1, w: 0, label: 3 }, { x: 0, y: phi, z: phiinv, w: 0, label: 5 }, { x: 0, y: phi, z: -phiinv, w: 0 , label: 2 }, { x: 0, y: -phi, z: phiinv, w: 0, label: 4 }, { x: 0, y: -phi, z: -phiinv, w: 0 , label: 1 }, { x: phiinv, y: 0, z: phi, w: 0 , label: 2}, { x: phiinv, y: 0, z: -phi, w: 0 , label: 4}, { x: -phiinv, y: 0, z: phi, w: 0 , label: 1}, { x: -phiinv, y: 0, z: -phi, w: 0 , label: 5}, { x: phi, y: phiinv, z:0, w: 0 , label: 1}, { x: phi, y: -phiinv, z:0, w: 0 , label: 5}, { x: -phi, y: phiinv, z:0, w: 0 , label: 4}, { x: -phi, y: -phiinv, z:0, w: 0 , label: 2}, ]; index_nodes(nodes); return nodes; } export const dodecahedron = () => { const nodes = make_dodecahedron_vertices(); const links = auto_detect_edges(nodes, 3); links.map((l) => l.label = 0); for( const p of [ 1, 2, 3, 4, 5 ]) { const tetran = nodes.filter((n) => n.label === p); const tetral = auto_detect_edges(tetran, 3); tetral.map((l) => l.label = p); links.push(...tetral); } return { name: 'dodecahedron', nodes: nodes, links: links, geometry: { node_size: 0.02, link_size: 0.02 }, options: [ { name: "none", links: [ 0 ]}, { name: "one tetrahedron", links: [ 0, 1 ] }, { name: "five tetrahedra", links: [ 0, 1, 2, 3, 4, 5 ] } ] } } export const build_all = () => { return [ dodecahedron(), cell5(), cell16(), tesseract(), cell24(), snub24cell(), cell600(), cell600_layered(), cell120_inscribed(), cell120_layered() ]; }