31:T6aa,function runStudy() { const n = 100; const results = _.times(n, () => { const marketSnapshots = generateMarketSnapshots(); const firstSnapshot = marketSnapshots[0]; const lastSnapshot = marketSnapshots[marketSnapshots.length - 1]; const overallPctChange = (lastSnapshot.value / firstSnapshot.value) - 1; const regularPurchasePctChanges = _.times(n, () => { const frequency = _.random(1, Math.floor(marketSnapshots.length / 2) + 1); const regularPurchases = generateRegularPurchases(marketSnapshots, frequency); const regularTrades = generateTradesFrom(marketSnapshots, regularPurchases); return _.sumBy(regularTrades, (trade) => { return (trade.fractionOfTotal * trade.pctChange); }) - 1; }); const avgRegularPurchasePctChange = _.mean(regularPurchasePctChanges); const randomPurchasePctChanges = _.times(n, () => { const frequency = _.random(1, Math.floor(marketSnapshots.length / 2) + 1); const randomPurchases = generateRandomPurchases(marketSnapshots, frequency); const randomTrades = generateTradesFrom(marketSnapshots, randomPurchases); return _.sumBy(randomTrades, (trade) => { return (trade.fractionOfTotal * trade.pctChange); }) - 1; }); const avgRandomPurchasePctChange = _.mean(randomPurchasePctChanges); return { overall: overallPctChange, regular: avgRegularPurchasePctChange, random: avgRandomPurchasePctChange }; }); const winningCounts = results.reduce((counts, result) => { const key = findWinningKey(result); return { ...counts, [key]: counts[key] + 1 } }, { overall: 0, regular: 0, random: 0 }); return winningCounts; }32:T6ff,runStudyForGraph = () => { const n = 8; const marketSnapshots = generateMarketSnapshots(); const firstSnapshot = marketSnapshots[0]; const lastSnapshot = marketSnapshots[marketSnapshots.length - 1]; const totalPctChange = (lastSnapshot.value / firstSnapshot.value) - 1; const regularTradeExperiments = []; const randomTradeExperiments = []; _.times(n, () => { const frequency = _.random(1, Math.floor(marketSnapshots.length / 2) + 1); const regularPurchases = generateRegularPurchases(marketSnapshots, frequency); const regularTrades = generateTradesFrom(marketSnapshots, regularPurchases); const regularTradePctChange = _.sumBy(regularTrades, (trade) => { return (trade.fractionOfTotal * trade.pctChange); }) - 1; regularTradeExperiments.push({ pctChange: regularTradePctChange, frequency: frequency, purchases: regularPurchases, trades: regularTrades }); }); _.times(n, () => { const randomPurchases = generateRandomPurchases(marketSnapshots); const randomTrades = generateTradesFrom(marketSnapshots, randomPurchases); const randomTradePctChange = _.sumBy(randomTrades, (trade) => { return (trade.fractionOfTotal * trade.pctChange); }) - 1; randomTradeExperiments.push({ pctChange: randomTradePctChange, purchases: randomPurchases, trades: randomTrades }); }); return { market: { snapshots: marketSnapshots, pctChange: totalPctChange }, regularTrading: { experiments: regularTradeExperiments, avgPctChange: _.meanBy(regularTradeExperiments, "pctChange") }, randomTrading: { experiments: randomTradeExperiments, avgPctChange: _.meanBy(randomTradeExperiments, "pctChange") } }; }33:T861,render = () => { rerenderButton; const study = runStudyForGraph(); const sectionDefinitions = [ ["Regular purchases", "regularTrading"], ["Random purchases", "randomTrading"] ]; const makePctChangeContainer = (elementName, pctChange) => { const className = pctChange >= 0 ? "positive" : "negative"; return html` <${elementName} class="pct-change ${className}">${formatChangeInPercentage(pctChange)} `; } const buildSection = (sectionName, pctChange, graphContainers) => { return html`

${sectionName} (${makePctChangeContainer("span", pctChange)})

${graphContainers}

`; }; const buildGraphContainer = ({ purchases, width: graphWidth = width, pctChange = null }) => { const graph = renderGraph({ marketSnapshots: study.market.snapshots, purchases: purchases, width: graphWidth }); const children = [graph]; if (pctChange != null) { const results = html`

${purchases.length} purchases: ${makePctChangeContainer("span", pctChange)}

`; children.push(results); } return html`

${children}

`; }; const marketSection = buildSection( "Overall market", study.market.pctChange, [ buildGraphContainer({ purchases: generatePurchases(study.market.snapshots, [0], (_, availableCash) => { return availableCash; }) }) ] ); const experimentSections = sectionDefinitions.map(([sectionName, studyProp]) => { return buildSection( sectionName, study[studyProp].avgPctChange, study[studyProp].experiments.map((experiment) => { return buildGraphContainer({ pctChange: experiment.pctChange, width: width / 4, purchases: experiment.purchases }); }) ) }); const sections = [marketSection].concat(experimentSections); return html`${sections}`; }34:[] 2f:{"title":"Experiments with dollar-cost averaging, part 2","cells":[{"id":0,"value":"md`# Experiments with dollar-cost averaging, part 2`","pinned":false,"hidden":false,"mode":"ojs"},{"id":664,"value":"viewof rerenderButton = html``","pinned":false,"hidden":false,"mode":"ojs"},{"id":317,"value":"render()","pinned":true,"hidden":false,"mode":"ojs"},{"id":590,"value":"/*\n{\n const results = runStudy();\n const winner = findWinningKey(results);\n return `${winner} is the winner!`;\n}\n*/","pinned":true,"hidden":false,"mode":"ojs"},{"id":624,"value":"/*import { worker } from \"@fil/worker\"*/","pinned":true,"hidden":false,"mode":"ojs"},{"id":306,"value":"md`---`","pinned":false,"hidden":false,"mode":"ojs"},{"id":86,"value":"md`## Data`","pinned":false,"hidden":false,"mode":"ojs"},{"id":553,"value":"$31","pinned":false,"hidden":false,"mode":"ojs"},{"id":50,"value":"$32","pinned":false,"hidden":false,"mode":"ojs"},{"id":4,"value":"generateMarketSnapshots = () => {\n const snapshots = [{ date: startDate, value: initialPricePerShare }];\n \n _.times(dateFns.differenceInDays(endDate, startDate), () => {\n const lastSnapshot = snapshots[snapshots.length - 1];\n snapshots.push({\n date: dateFns.addDays(lastSnapshot.date, 1),\n value: lastSnapshot.value + _.random(-marketVariancePerDay, marketVariancePerDay)\n });\n });\n \n return snapshots;\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":30,"value":"generateRegularPurchases = (marketSnapshots, frequency) => {\n const snapshotIndices = _.range(0, marketSnapshots.length, frequency);\n const availableCashPerPurchase = availableCash / snapshotIndices.length;\n return generatePurchases(marketSnapshots, snapshotIndices, (snapshot, availableCash, isFinal) => {\n const pricePerShare = snapshot.value;\n return Math.floor(availableCashPerPurchase / pricePerShare) * pricePerShare\n });\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":37,"value":"generateRandomPurchases = (marketSnapshots) => {\n const shuffledIndices = _.shuffle(_.range(0, marketSnapshots.length));\n const randomLength = _.random(marketSnapshots.length);\n const randomIndices = shuffledIndices.slice(0, randomLength).sort((a, b) => a - b);\n return generatePurchases(marketSnapshots, randomIndices, (snapshot, availableCash, isFinal) => {\n if (isFinal) {\n return availableCash;\n } else {\n return availableCash * _.random(randomPurchaseVariance.start, randomPurchaseVariance.end, true);\n }\n });\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":34,"value":"generatePurchases = (marketSnapshots, snapshotIndices, determineValue) => {\n const result = snapshotIndices.reduce(({ availableCash, purchases }, snapshotIndex, index) => {\n const snapshot = marketSnapshots[snapshotIndex];\n const value = determineValue(snapshot, availableCash, index === snapshotIndices.length - 1);\n const newPurchase = {\n snapshot: snapshot,\n date: snapshot.date,\n value: value\n };\n return {\n purchases: purchases.concat([newPurchase]),\n availableCash: availableCash - value\n };\n }, { availableCash: availableCash, purchases: [] });\n return result.purchases;\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":64,"value":"generateTradesFrom = (marketSnapshots, purchases) => {\n const lastSnapshot = marketSnapshots[marketSnapshots.length - 1];\n const purchaseTotal = _.sumBy(purchases, \"value\");\n return purchases.map(purchase => {\n return {\n date: purchase.date,\n pctChange: lastSnapshot.value / purchase.snapshot.value,\n fractionOfTotal: purchase.value / purchaseTotal\n };\n });\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":12,"value":"numberOfMonths = 12","pinned":false,"hidden":false,"mode":"ojs"},{"id":8,"value":"startDate = new Date(2020, 2, 1, 0, 0, 0)","pinned":false,"hidden":false,"mode":"ojs"},{"id":10,"value":"endDate = dateFns.addMonths(startDate, numberOfMonths)","pinned":false,"hidden":false,"mode":"ojs"},{"id":16,"value":"initialPricePerShare = 1000","pinned":false,"hidden":false,"mode":"ojs"},{"id":26,"value":"marketVariancePerDay = 20","pinned":false,"hidden":false,"mode":"ojs"},{"id":31,"value":"availableCash = 1000000","pinned":false,"hidden":false,"mode":"ojs"},{"id":41,"value":"randomPurchaseVariance = ({ start: 0.01, end: 0.25 })","pinned":false,"hidden":false,"mode":"ojs"},{"id":657,"value":"findWinningKey = (results) => {\n return _.sortBy(\n _.toPairs(results).map(([key, value]) => ({ key, value })),\n ({ key, value }) => value\n ).reverse()[0].key;\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":320,"value":"md`## Graph`","pinned":false,"hidden":false,"mode":"ojs"},{"id":156,"value":"$33","pinned":false,"hidden":false,"mode":"ojs"},{"id":98,"value":"renderGraph = (graphOptions) => {\n const svg = d3.create(\"svg\")\n .attr(\"viewBox\", [0, 0, graphOptions.width, height])\n .attr(\"width\", graphOptions.width)\n .attr(\"height\", height)\n \n addAxesLayerTo(svg, graphOptions);\n addMarketSnapshotsLayerTo(svg, graphOptions);\n addPurchasesLayerTo(svg, graphOptions);\n \n return svg.node();\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":187,"value":"addAxesLayerTo = (svg, graphOptions) => {\n svg.append(\"g\").call(addXAxisTo, graphOptions);\n svg.append(\"g\").call(addYAxisTo, graphOptions);\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":184,"value":"addMarketSnapshotsLayerTo = (svg, graphOptions) => {\n const x = makeXScale(graphOptions);\n const y = makeYScale(graphOptions);\n svg\n .append(\"g\")\n .append(\"path\")\n .datum(graphOptions.marketSnapshots)\n .attr(\"fill\", \"none\")\n .attr(\"stroke\", \"black\")\n .attr(\"stroke-width\", Math.max(1, Math.floor(graphOptions.width / 400)))\n .attr(\"stroke-linejoin\", \"round\")\n .attr(\"stroke-linecap\", \"round\")\n .attr(\"d\", polyLine(x, y));\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":180,"value":"addPurchasesLayerTo = (svg, graphOptions) => {\n const lastSnapshot = graphOptions.marketSnapshots[graphOptions.marketSnapshots.length - 1];\n const x = makeXScale(graphOptions);\n const y = makeYScale(graphOptions);\n \n svg\n .append(\"g\")\n .selectAll(\"line\")\n .data(graphOptions.purchases)\n .enter().append(\"line\")\n .attr(\"fill\", \"none\")\n .attr(\"stroke\", p => {\n const diff = lastSnapshot.value - p.snapshot.value;\n if (diff >= 0) {\n return \"rgba(0, 128, 0, 0.5)\";\n } else {\n return \"rgba(255, 0, 0, 0.5)\";\n }\n })\n .attr(\"stroke-width\", 1)\n .attr(\"x1\", p => x(p.snapshot.date))\n .attr(\"y1\", p => y(p.snapshot.value))\n .attr(\"x2\", x(lastSnapshot.date))\n .attr(\"y2\", y(lastSnapshot.value));\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":176,"value":"addXAxisTo = (g, graphOptions) => {\n return g\n .attr(\"transform\", `translate(0, ${height - margin.bottom})`)\n .call(\n d3\n .axisBottom(makeXScale(graphOptions))\n .ticks(graphOptions.width / 80)\n .tickSizeOuter(0)\n )\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":173,"value":"makeXScale = (graphOptions) => {\n return d3\n .scaleTime()\n .domain(d3.extent(graphOptions.marketSnapshots, d => d.date))\n .range([margin.left, graphOptions.width - margin.right]) \n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":170,"value":"addYAxisTo = (g, graphOptions) => {\n return g\n .attr(\"transform\", `translate(${margin.left}, 0)`)\n .call(d3.axisLeft(makeYScale(graphOptions)))\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":165,"value":"makeYScale = (graphOptions) => {\n return d3\n .scaleLinear()\n .domain(d3.extent(graphOptions.marketSnapshots, d => d.value))\n .nice()\n .range([height - margin.bottom, margin.top]);\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":197,"value":"polyLine = (x, y) => {\n return d3.line()\n .defined(d => !isNaN(d.value))\n .x(d => x(d.date))\n .y(d => y(d.value))\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":191,"value":"margin = ({ top: 20, right: 40, bottom: 30, left: 40 })","pinned":false,"hidden":false,"mode":"ojs"},{"id":194,"value":"height = 200","pinned":false,"hidden":false,"mode":"ojs"},{"id":268,"value":"formatChangeInPercentage = (ratio) => {\n const format = new Intl.NumberFormat('en-US', {\n style: 'percent',\n minimumFractionDigits: 2,\n maximumFractionDigits: 2\n });\n const delta = ratio;\n const formattedDelta = format.format(delta);\n \n if (delta >= 0) {\n return html`+${formattedDelta}`\n } else {\n return `${formattedDelta}`;\n }\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":248,"value":"html``","pinned":false,"hidden":false,"mode":"ojs"},{"id":91,"value":"md`## Libraries`","pinned":false,"hidden":false,"mode":"ojs"},{"id":99,"value":"d3 = require('d3@5', 'd3-array')","pinned":false,"hidden":false,"mode":"ojs"},{"id":5,"value":"dateFns = import('date-fns@2')","pinned":false,"hidden":false,"mode":"ojs"},{"id":14,"value":"_ = require('lodash@4')","pinned":false,"hidden":false,"mode":"ojs"}],"files":"$W34","stdlib":"1","titling":"auto"}