mirror of
https://github.com/multipleof4/lynchmark.git
synced 2026-05-18 04:32:12 +00:00
20 lines
787 B
JavaScript
20 lines
787 B
JavaScript
async function createStreamVisualizer(it, { maxPoints, alpha, width, height, yDomain }) {
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const [{ scaleLinear, line, extent }] = await Promise.all([import('https://cdn.skypack.dev/d3')]);
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const data = [];
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let prevEma;
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for await (const { timestamp, value } of it) {
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prevEma = prevEma === undefined ? value : alpha * value + (1 - alpha) * prevEma;
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data.push({ timestamp, value, ema: prevEma });
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if (data.length > maxPoints) data.shift();
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}
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const x = scaleLinear().domain(extent(data, d => d.timestamp)).range([0, width]);
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const y = scaleLinear().domain(yDomain).range([height, 0]);
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const path = line().x(d => x(d.timestamp)).y(d => y(d.ema))(data);
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return { data, path };
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}
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export default createStreamVisualizer;
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// Generation time: 1.461s
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// Result: PASS
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