mirror of
https://github.com/lynchmarkHQ/lynchmark.com.git
synced 2026-10-18 01:37:54 +00:00
19 lines
773 B
JavaScript
19 lines
773 B
JavaScript
export const createStreamVisualizer = async (stream, { maxPoints, alpha, width, height, yDomain }) => {
|
|
const { scaleLinear, line } = await import('https://esm.sh/d3');
|
|
const data = [];
|
|
|
|
for await (const { timestamp: t, value: v } of stream) {
|
|
const prev = data.at(-1);
|
|
data.push({ timestamp: t, value: v, ema: prev ? alpha * v + (1 - alpha) * prev.ema : v });
|
|
if (data.length > maxPoints) data.shift();
|
|
}
|
|
|
|
if (!data.length) return { data, path: '' };
|
|
|
|
const x = scaleLinear().domain([data[0].timestamp, data.at(-1).timestamp]).range([0, width]);
|
|
const y = scaleLinear().domain(yDomain).range([height, 0]);
|
|
const gen = line().x(d => x(d.timestamp)).y(d => y(d.ema));
|
|
|
|
return { data, path: gen(data) };
|
|
};
|
|
export default createStreamVisualizer; |