2d:null 2e:["$","title",null,{"children":"Patterns in Conway’s Game of Life | Mike Bostock | Observable"}] 33:T5a4,gun = view(38, 18, [ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,1,1,0, 0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,1,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,1,1,0, 0,1,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,1,1,0,0,0,0,0,0,0,0,1,0,0,0,1,0,1,1,0,0,0,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 ])34:Ta7e,function* view(n, m, grid, vx = 0, vy = 0) { const pad = 1; const delay = 750; const radius = 20; const svg = DOM.svg(n * radius + 1, m * radius + 1); svg.setAttribute("viewBox", [pad * radius - 0.5, pad * radius - 0.5, n * radius + 1, m * radius + 1]); svg.setAttribute("stroke", "lightgray"); svg.style.display = "block"; let grid1 = new Array((n + pad * 2) * (m + pad * 2)).fill(0), grid2 = grid1.slice(); for (let y = 0; y < m; ++y) { for (let x = 0; x < n; ++x) { grid1[(y + pad) * (n + pad * 2) + x + pad] = grid[y * n + x]; } } n += pad * 2, m += pad * 2; for (let y = 0; y < m; ++y) { for (let x = 0; x < n; ++x) { const rect = svg.appendChild(DOM.element("svg:rect")); rect.setAttribute("width", radius); rect.setAttribute("height", radius); rect.setAttribute("x", x * radius); rect.setAttribute("y", y * radius); } } let changed; let ox = 0; let oy = 0; do { changed = false; if (vx || vy) { let then = Date.now(); requestAnimationFrame(function slide() { const t = (Date.now() - then) / delay; for (let y = 0, i = 0; y < m; ++y) { const y1 = (y + oy + vy * t) % m; for (let x = 0; x < n; ++x, ++i) { const x1 = (x + ox + vx * t) % n; const rect = svg.childNodes[i]; rect.setAttribute("x", (x1 < 0 ? x1 + n : x1) * radius); rect.setAttribute("y", (y1 < 0 ? y1 + m : y1) * radius); } } if (t < 1) requestAnimationFrame(slide); }); } yield Promises.tick(delay, svg); ox += vx; oy += vy; for (let y = 0; y < m; ++y) { for (let x = 0; x < n; ++x) { let i = y * n + x; let s1 = grid1[i]; let k = -s1; for (let dy = -1; dy <= 1; ++dy) { let yd = y + dy; if (vy) { if (0 > yd) yd = m - 1; else if (yd >= m) yd = 0; } else { if (0 > yd) continue; else if (yd >= m) break; } for (let dx = -1; dx <= 1; ++dx) { let xd = x + dx; if (vx) { if (0 > xd) xd = n - 1; else if (xd >= n) xd = 0; } else { if (0 > xd) continue; else if (xd >= n) break; } k += grid1[yd * n + xd]; } } let s2 = +(s1 === 1 ? 2 <= k && k <= 3 : k === 3); if (s1 !== s2) changed = true; grid2[y * n + x] = s2; svg.childNodes[i].setAttribute("fill", s1 ? "black" : "white"); } } [grid1, grid2] = [grid2, grid1]; } while (changed); }35:[] 31:{"id":"50d1940776f1e794","slug":"patterns-in-conways-game-of-life","title":"Patterns in Conway’s Game of Life","thumbnail":"d128b5d8e3a29075dded63cae855d6efc27c2d3e06083ce2611aa909d043fecf","access_level":"public","create_time":"$D2017-12-03T00:51:40.673Z","update_time":"$D2017-12-15T05:10:37.186Z","view_time":null,"first_public_time":"$D2017-12-03T07:41:09.179Z","fork":false,"stars":17,"starred":false,"owner":{"type":"team","id":"8c2e47252fd4995c","login":"mbostock","name":"Mike Bostock","avatar_url":"https://avatars-next.observableusercontent.com/7dbba99ced40bd5ab8013c99b1a11da61231bce321ba1148a9d16ad0f121550a","tier":"pro_2026"},"version":420,"publish_version":420,"role":null,"authored":false,"authors":[{"type":"individual","id":"074c414ad1d825f5","login":"mbostock","name":"Mike Bostock","avatar_url":"https://avatars-next.observableusercontent.com/7dbba99ced40bd5ab8013c99b1a11da61231bce321ba1148a9d16ad0f121550a","tier":null}],"members":[{"type":"individual","id":"074c414ad1d825f5","login":"mbostock","name":"Mike Bostock","avatar_url":"https://avatars-next.observableusercontent.com/7dbba99ced40bd5ab8013c99b1a11da61231bce321ba1148a9d16ad0f121550a","tier":null,"role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":6,"collection":null,"type":"notebook","body":{"title":"Patterns in Conway’s Game of Life","cells":[{"id":0,"value":"md`# Patterns in Conway’s Game of Life`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":112,"value":"md`## Still Life\n\nPatterns that are static.`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":116,"value":"block = view(4, 4, [\n 0,0,0,0,\n 0,1,1,0,\n 0,1,1,0,\n 0,0,0,0\n])","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":125,"value":"boat = view(5, 5, [\n 0,0,0,0,0,\n 0,1,1,0,0,\n 0,1,0,1,0,\n 0,0,1,0,0,\n 0,0,0,0,0\n])","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":195,"value":"tub = view(5, 5, [\n 0,0,0,0,0,\n 0,0,1,0,0,\n 0,1,0,1,0,\n 0,0,1,0,0,\n 0,0,0,0,0\n])","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":140,"value":"beehive = view(6, 5, [\n 0,0,0,0,0,0,\n 0,0,1,1,0,0,\n 0,1,0,0,1,0,\n 0,0,1,1,0,0,\n 0,0,0,0,0,0\n])","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":138,"value":"loaf = view(6, 6, [\n 0,0,0,0,0,0,\n 0,0,1,1,0,0,\n 0,1,0,0,1,0,\n 0,0,1,0,1,0,\n 0,0,0,1,0,0,\n 0,0,0,0,0,0\n])","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":85,"value":"md`## Oscillators\n\nPatterns that repeat after a fixed number of iterations.`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":30,"value":"blinker = view(5, 5, [\n 0,0,0,0,0,\n 0,0,0,0,0,\n 0,1,1,1,0,\n 0,0,0,0,0,\n 0,0,0,0,0\n])","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":72,"value":"beacon = view(6, 6, [\n 0,0,0,0,0,0,\n 0,1,1,0,0,0,\n 0,1,0,0,0,0,\n 0,0,0,0,1,0,\n 0,0,0,1,1,0,\n 0,0,0,0,0,0\n])","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":78,"value":"toad = view(6, 6, [\n 0,0,0,0,0,0,\n 0,0,0,1,0,0,\n 0,1,0,0,1,0,\n 0,1,0,0,1,0,\n 0,0,1,0,0,0,\n 0,0,0,0,0,0\n])","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":89,"value":"pulsar = view(17, 17, [\n 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,\n 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,\n 0,0,0,0,1,1,1,0,0,0,1,1,1,0,0,0,0,\n 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,\n 0,0,1,0,0,0,0,1,0,1,0,0,0,0,1,0,0,\n 0,0,1,0,0,0,0,1,0,1,0,0,0,0,1,0,0,\n 0,0,1,0,0,0,0,1,0,1,0,0,0,0,1,0,0,\n 0,0,0,0,1,1,1,0,0,0,1,1,1,0,0,0,0,\n 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,\n 0,0,0,0,1,1,1,0,0,0,1,1,1,0,0,0,0,\n 0,0,1,0,0,0,0,1,0,1,0,0,0,0,1,0,0,\n 0,0,1,0,0,0,0,1,0,1,0,0,0,0,1,0,0,\n 0,0,1,0,0,0,0,1,0,1,0,0,0,0,1,0,0,\n 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,\n 0,0,0,0,1,1,1,0,0,0,1,1,1,0,0,0,0,\n 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,\n 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0\n])","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":205,"value":"pd = view(11, 18, [\n 0,0,0,0,0,0,0,0,0,0,0,\n 0,0,0,0,0,0,0,0,0,0,0,\n 0,0,0,0,0,0,0,0,0,0,0,\n 0,0,0,0,0,0,0,0,0,0,0,\n 0,0,0,0,0,1,0,0,0,0,0,\n 0,0,0,0,0,1,0,0,0,0,0,\n 0,0,0,0,1,0,1,0,0,0,0,\n 0,0,0,0,0,1,0,0,0,0,0,\n 0,0,0,0,0,1,0,0,0,0,0,\n 0,0,0,0,0,1,0,0,0,0,0,\n 0,0,0,0,0,1,0,0,0,0,0,\n 0,0,0,0,1,0,1,0,0,0,0,\n 0,0,0,0,0,1,0,0,0,0,0,\n 0,0,0,0,0,1,0,0,0,0,0,\n 0,0,0,0,0,0,0,0,0,0,0,\n 0,0,0,0,0,0,0,0,0,0,0,\n 0,0,0,0,0,0,0,0,0,0,0,\n 0,0,0,0,0,0,0,0,0,0,0\n])","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":183,"value":"md`## Spaceships\n\nPatterns that move.`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":186,"value":"glider = view(8, 7, [\n 0,0,0,0,0,0,0,0,\n 0,0,0,0,0,0,0,0,\n 0,0,0,0,0,0,0,0,\n 0,0,0,0,0,1,0,0,\n 0,0,0,1,0,1,0,0,\n 0,0,0,0,1,1,0,0,\n 0,0,0,0,0,0,0,0\n], -1 / 4, -1 / 4)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":190,"value":"lwss = view(9, 7, [\n 0,0,0,0,0,0,0,0,0,\n 0,0,0,1,0,0,1,0,0,\n 0,0,1,0,0,0,0,0,0,\n 0,0,1,0,0,0,1,0,0,\n 0,0,1,1,1,1,0,0,0,\n 0,0,0,0,0,0,0,0,0,\n 0,0,0,0,0,0,0,0,0\n], 1 / 2, 0)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":348,"value":"mwss = view(10, 9, [\n 0,0,0,0,0,0,0,0,0,0,\n 0,0,0,0,0,1,0,0,0,0,\n 0,0,0,1,0,0,0,1,0,0,\n 0,0,1,0,0,0,0,0,0,0,\n 0,0,1,0,0,0,0,1,0,0,\n 0,0,1,1,1,1,1,0,0,0,\n 0,0,0,0,0,0,0,0,0,0,\n 0,0,0,0,0,0,0,0,0,0,\n 0,0,0,0,0,0,0,0,0,0\n], 1 / 2, 0)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":355,"value":"md`## Guns\n\nStationary patterns that emit spaceships.`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":357,"value":"$33","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":3,"value":"$34","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W35","stdlib":"1","titling":"auto"}} 32:"$31:body"