2b:null 2c:["$","title",null,{"children":"Faster LCG / PCG? | Fil | Observable"}] 31:T56e,// import { pcgrandom_job as pcgAA } from "@jrus/permuted-congruential-generator" pcgAA = { // Note that the index order [0, 1, 2, 3] is little-endian const eps = Math.pow(2, -32), lo = 0xFFFF, m0 = 0x7F2D, m1 = 0x4C95, m2 = 0xF42D, m3 = 0x5851, // 6364136223846793005 a0 = 0x814F, a1 = 0xF767, a2 = 0x7B7E, a3 = 0x1405, // 1442695040888963407 state = Uint16Array.from({length: 4}, () => Math.random() * 0x10000); // random seed return function pcgrandom(){ // Advance internal state const s0 = state[0], s1 = state[1], s2 = state[2], s3 = state[3], new0 = a0 + (s0*m0 & lo), new1 = a1 + (new0 >>> 16) + ((s0*m1 & lo) + (s0*m0 >>> 16)) + (s1*m0 & lo), new2 = a2 + (new1 >>> 16) + ((s0*m2 & lo) + (s0*m1 >>> 16)) + ((s1*m1 & lo) + (s1*m0 >>> 16)) + (s2*m0 & lo), new3 = a3 + (new2 >>> 16) + ((s0*m3 & lo) + (s0*m2 >>> 16)) + ((s1*m2 & lo) + (s1*m1 >>> 16)) + ((s2*m1 & lo) + (s2*m0 >>> 16)) + (s3*m0 & lo); state[0] = new0; state[1] = new1; state[2] = new2; state[3] = new3; // Calculate output function (XSH RR), uses old state const xorshifted = (s3 << 21) + ((s3 >> 2 ^ s2) << 5) + ((s2 >> 2 ^ s1) >> 11), out_int32 = xorshifted >>> (s3 >> 11) | xorshifted << (-(s3 >> 11) & 31); return eps * (out_int32 >>> 0); } }32:T5c9,// import { pcgrandom as pcgB } from "@jrus/permuted-congruential-generator" pcgB = { // Note that the index order [0, 1, 2, 3] is little-endian const eps = Math.pow(2, -32), m0 = 0x7F2D, m1 = 0x4C95, m2 = 0xF42D, m3 = 0x5851, // 6364136223846793005 a0 = 0x814F, a1 = 0xF767, a2 = 0x7B7E, a3 = 0x1405, // 1442695040888963407 state = Uint16Array.from({length: 4}, () => Math.random() * 0x10000); // random seed return function pcgrandom() { // Advance internal state const s0 = state[0], s1 = state[1], s2 = state[2], s3 = state[3], new0 = a0 + m0*s0 |0, new1 = a1 + m0*s1 + (m1*s0 + (new0 >>> 16)) |0, new2 = a2 + m0*s2 + m1*s1 + (m2*s0 + (new1 >>> 16)) |0, new3 = a3 + m0*s3 + (m1*s2 + m2*s1) + (m3*s0 + (new2 >>> 16)); state[0] = new0, state[1] = new1, state[2] = new2; state[3] = new3; // Calculate output function (XSH RR), uses old state const xorshifted = (s3 << 21) + ((s3 >> 2 ^ s2) << 5) + ((s2 >> 2 ^ s1) >> 11), out_int32 = xorshifted >>> (s3 >> 11) | xorshifted << (-(s3 >> 11) & 31); return eps * (out_int32 >>> 0); } } // In the code above both new2 and new3 can overflow 32 bits, and the // resulting carry bits are lost, but we don’t need to care because // those bits are larger than our 64-bit number anyway. // // new1 can't overflow 32 bits because m0 and m1 are small: // a1 + m0*s1 + m1*s0 + carry // <= (2 + 0x7F2D + 0x4C95) * 0xFFFF == 0xCBC3343C33:[] 2f:{"id":"b1aa7c52fc50a054","slug":null,"title":"Faster LCG / PCG?","thumbnail":"c09926890b7d5e3d6ce30567af5afe0a56d15a3683c3f40d9bf571b4a8c8863c","access_level":"unlisted","create_time":"$D2020-08-22T06:51:55.937Z","update_time":"$D2020-09-15T06:36:50.604Z","view_time":null,"first_public_time":null,"has_unpublished_edits":null,"fork":false,"stars":0,"starred":false,"owner":{"type":"team","id":"da2a32154638c457","login":"fil","name":"Fil","avatar_url":"https://avatars-next.observableusercontent.com/d5b1777907117a2bdf2a07eb98600d7a9beb21639fde42b9753e95c88c7731a6","tier":"starter_2024"},"version":466,"publish_version":466,"role":null,"authored":false,"authors":[{"type":"individual","id":"45a379fcfcb14253","login":"fil","name":"Fil","avatar_url":"https://avatars-next.observableusercontent.com/d5b1777907117a2bdf2a07eb98600d7a9beb21639fde42b9753e95c88c7731a6","tier":null}],"members":[{"type":"individual","id":"45a379fcfcb14253","login":"fil","name":"Fil","avatar_url":"https://avatars-next.observableusercontent.com/d5b1777907117a2bdf2a07eb98600d7a9beb21639fde42b9753e95c88c7731a6","tier":null,"role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":0,"collection":null,"type":"notebook","body":{"title":"Faster LCG / PCG?","cells":[{"id":0,"value":"md`# Faster LCG / PCG?\n\n| browser | reporter | lcg | lcgA | lcgB | lcgC | lcgDª | lcgEª | lcgF | lcgG |/| pcgA | pcgB |/| Math |\n|-\n| chrome/mac |@fil | 28.5 | 65.5 | 44.0 | **77.7** | 41.7 | 41.2 | 41.2 | 43.3 || **59.3** | 44.0 || 158.3 |\n| firefox/mac | @fil | 9.6 | 13.9 | 14.7 | 14.4 | 15.4 | 15.1 | 15.1 | **15.9** || 11.6 | 12.7 || 16.1 |\n| safari/mac |@fil | 25.3 | 128.2 | 66.7 | 133.3 | 243.9 | 208.3 | **212.1** | **217.4** || **105.3** | 44.2 || 500 |\n| chrome/iPhone | @fil | 10.4 | 48.4 | 31.9 | 46.9 | 142.9 | 128.3 | **140.8** | **138.9** || **58.1** | 23.4 || 87.7 |\n| safari/iPhone | @fil | 10.2 | 48.7 | 27.9 | 49.3 | 144.9 | 131.6 | **131.6** | **133.3** || **59.2** | 24.4 || 102.0 |\n| firefox/iPhone | @fil | 10.6 | 47.6 | 29.9 | 48.1 | 135.1 | 137.0 | **133.3** | **133.3** || **59.2** | 24.4 || 102.0 |\n\nª return numbers -.5 < u < .5`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":96,"value":"lcg = {\n const a = 1664525;\n const c = 1013904223;\n const m = 4294967296; // 2^32\n\n return function lcg(s) {\n if (s === undefined) s = Math.random();\n if (!(0 <= s && s < 1)) throw new RangeError(\"invalid seed\");\n s = Math.floor(m * s);\n return () => (s = (s * a + c) % m) / m;\n };\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":106,"value":"perf(lcg(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":27,"value":"lcgA = {\n const a = 1664525;\n const c = 1013904223;\n const m = 4294967296; // 2^32\n\n const A = new Uint32Array(1);\n return function lcg(s) {\n if (s === undefined) s = Math.random();\n if (!(0 <= s && s < 1)) throw new RangeError(\"invalid seed\");\n A[0] = Math.floor(m * s);\n return () => ((A[0] = A[0] * a + c), A[0]) / m;\n };\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":101,"value":"perf(lcgA(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":151,"value":"lcgB = {\n const a = 1664525;\n const c = 1013904223;\n const m = 4294967296; // 2^32\n\n return function lcg(s) {\n if (s === undefined) s = Math.random();\n if (!(0 <= s && s < 1)) throw new RangeError(\"invalid seed\");\n s = Math.floor(m * s);\n return () => (s = (s * a + c) >>> 0) / m;\n };\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":155,"value":"perf(lcgB(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":168,"value":"lcgC = {\n const mul = 0x19660D,\n inc = 0x3C6EF35F,\n A = Uint32Array.from([0]),\n eps = Math.pow(2, -32);\n return function lcg(s = Math.random()) {\n if (!(0 <= s && s < 1)) throw new RangeError(\"invalid seed\");\n A[0] = Math.floor(s / eps);\n return () => ((A[0] = A[0] * mul + inc), eps * A[0]);\n };\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":170,"value":"perf(lcgC(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":185,"value":"lcgD = {\n const mul = 0x19660D,\n inc = 0x3C6EF35F,\n lo32 = 0xFFFFFFFF,\n eps = Math.pow(2, -32);\n return function(seed) {\n let state = Math.floor((lo32 + 1) * +seed);\n return () => eps * (state = (mul * state + inc) & lo32);\n };\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":209,"value":"perf(lcgD(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":237,"value":"lcgE = {\n const mul = 0x19660D,\n inc = 0x3C6EF35F,\n eps = Math.pow(2, -32);\n return function lcg(s = Math.random()) {\n if (!(0 <= s && s < 1)) throw new RangeError(\"invalid seed\");\n s = Math.floor(s / eps);\n return () => ((s = (s * mul + inc) & 0xFFFFFFFF), eps * s);\n };\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":247,"value":"perf(lcgE(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":323,"value":"lcgF = {\n const mul = 0x19660D;\n const inc = 0x3C6EF35F;\n const lo32 = 0xFFFFFFFF;\n const eps = Math.pow(2, -32);\n return function lcg(seed = Math.random()) {\n if (0 > seed || seed >= 1) throw new RangeError(\"invalid seed\");\n let state = Math.floor((1 + lo32) * seed);\n return () => eps * ((state = (mul * state + inc) & lo32) >>> 0);\n };\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":334,"value":"perf(lcgF(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":350,"value":"lcgG = {\n //@jrus\n const mul = 0x19660D,\n inc = 0x3C6EF35F,\n eps = 1 / 0x100000000;\n return function lcg(seed = Math.random()) {\n if (!(0 <= seed && seed < 1)) throw new RangeError(\"invalid seed\");\n let state = (seed / eps) | 0;\n return () => ((state = (mul * state + inc) | 0), eps * (state >>> 0));\n };\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":353,"value":"perf(lcgG(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":381,"value":"lcgH = {\n const mul = 0x19660D,\n inc = 0x3C6EF35F,\n eps = 1 / 0x100000000;\n return function lcg(seed = Math.random()) {\n if (!(0 <= seed && seed < 1)) throw new RangeError(\"invalid seed\");\n let state = (seed / eps) | 0;\n return () => eps * ((state = (mul * state + inc) | 0) >>> 0);\n };\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":401,"value":"perf(lcgH(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":413,"value":"lcgI = {\n const mul = 0x19660D,\n inc = 0x3C6EF35F,\n eps = 1 / 0x100000000;\n return function lcg(seed = Math.random()) {\n if (!(0 <= seed && seed < 1)) throw new RangeError(\"invalid seed\");\n let state = (seed / eps) | 0;\n return () => eps * (state = (mul * state + inc) >>> 0);\n };\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":417,"value":"perf(lcgI(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":421,"value":"lcgJ = {\n const mul = 0x19660D,\n inc = 0x3C6EF35F,\n eps = 1 / 0x100000000;\n return function lcg(seed = Math.random()) {\n if (!(0 <= seed && seed < 1)) throw new RangeError(\"invalid seed\");\n let state = (seed / eps) | 0,\n s1;\n return () => (state = (inc + mul * state) >>> 0) * eps;\n };\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":423,"value":"perf(lcgJ(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":148,"value":"md`Consistency checks:`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":131,"value":"Array.from({ length: 5 }, lcg(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":121,"value":"Array.from({ length: 5 }, lcgA(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":145,"value":"Array.from({ length: 5 }, lcgB(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":178,"value":"Array.from({ length: 5 }, lcgC(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":188,"value":"Array.from({ length: 5 }, lcgD(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":239,"value":"Array.from({ length: 5 }, lcgE(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":331,"value":"Array.from({ length: 5 }, lcgF(0.5))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":60,"value":"import { pcgrandom as pcgA } from \"@jobleonard/permuted-congruential-generator\"","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":55,"value":"perf(pcgA)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":376,"value":"$31","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":438,"value":"perf(pcgAA)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":51,"value":"$32","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":65,"value":"perf(pcgB)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":48,"value":"perf(Math.random)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":31,"value":"async function perf(random) {\n await Promises.delay(100);\n const n = 1e7;\n const u = Array.from({ length: 5 }, random).map(d => +d.toFixed(6));\n const t0 = performance.now();\n for (let a = 0; a < n; a++) random();\n const time = performance.now() - t0;\n return md`${(n / 1e3 / time).toFixed(1)} m/s\n ${u.join(', ')}`;\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":195,"value":"d3 = require(\"d3\")","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W33","stdlib":"1","titling":"auto"}} 30:"$2f:body"