feat(demo): replace source waveforms with simulated data

src/data/simulatedWaveforms.ts

@@ -0,0 +1,121 @@
+import type { WaveformData, WaveformPoint, WaveformSeries } from '../types'
+
+const POINT_COUNT = 1_000
+const START_TIME = -5
+const END_TIME = 5
+const TWO_PI = Math.PI * 2
+
+type SignalGenerator = (time: number, noise: number) => number
+type ErrorGenerator = (time: number, value: number) => Pick<
+  WaveformPoint,
+  'error' | 'lowerError' | 'upperError'
+>
+
+interface SimulatedSeriesDefinition
+  extends Pick<
+    WaveformSeries,
+    'id' | 'name' | 'unit' | 'lineType' | 'pointType' | 'errorBar'
+  > {
+  signal: SignalGenerator
+  errors?: ErrorGenerator
+}
+
+function createSeededNoise(seed: number) {
+  let state = seed >>> 0
+  return () => {
+    state = (Math.imul(state, 1_664_525) + 1_013_904_223) >>> 0
+    return state / 0x1_0000_0000 - 0.5
+  }
+}
+
+function createPoints(
+  signal: SignalGenerator,
+  noise: () => number,
+  errors?: ErrorGenerator,
+): WaveformPoint[] {
+  return Array.from({ length: POINT_COUNT }, (_, index) => {
+    const time = START_TIME + (index * (END_TIME - START_TIME)) / (POINT_COUNT - 1)
+    const value = signal(time, noise())
+    return {
+      x: time,
+      y: value,
+      ...(errors?.(time, value) ?? {}),
+    }
+  })
+}
+
+const seriesDefinitions: SimulatedSeriesDefinition[] = [
+  {
+    id: 'simulated-sine',
+    name: '正弦基波',
+    unit: 'V',
+    lineType: 'none',
+    pointType: 'triangle',
+    errorBar: { visible: true },
+    signal: (time) => 1.2 * Math.sin(TWO_PI * 0.8 * time),
+    errors: (time) => ({
+      lowerError: 0.06 + 0.015 * Math.abs(Math.sin(time)),
+      upperError: 0.08 + 0.02 * Math.abs(Math.cos(time)),
+    }),
+  },
+  {
+    id: 'simulated-harmonic',
+    name: '谐波扰动',
+    unit: 'V',
+    lineType: 'linear',
+    pointType: 'none',
+    signal: (time) =>
+      0.9 * Math.sin(TWO_PI * 0.55 * time) + 0.28 * Math.sin(TWO_PI * 2.2 * time + 0.4),
+  },
+  {
+    id: 'simulated-damped',
+    name: '阻尼振荡',
+    unit: 'A',
+    lineType: 'linear',
+    pointType: 'none',
+    signal: (time) => {
+      const elapsed = time + 5
+      return 2.4 * Math.exp(-elapsed * 0.28) * Math.sin(TWO_PI * 1.25 * elapsed)
+    },
+  },
+  {
+    id: 'simulated-step',
+    name: '阶跃响应',
+    unit: 'V',
+    lineType: 'linear',
+    pointType: 'none',
+    signal: (time) => (time < 0 ? 0 : 1 - Math.exp(-time * 2.4)),
+  },
+  {
+    id: 'simulated-pulse',
+    name: '脉冲响应',
+    unit: 'V',
+    lineType: 'linear',
+    pointType: 'none',
+    signal: (time) => 1.8 * Math.exp(-((time - 0.75) ** 2) / 0.12),
+  },
+  {
+    id: 'simulated-noise',
+    name: '带噪信号',
+    unit: 'A',
+    lineType: 'linear',
+    pointType: 'diamond',
+    errorBar: { visible: true },
+    signal: (time, noise) => 0.7 * Math.sin(TWO_PI * 0.45 * time) + noise * 0.36,
+    errors: () => ({ error: 0.12 }),
+  },
+]
+
+export function createSimulatedWaveformData(): WaveformData {
+  const noise = createSeededNoise(0x5eed1234)
+  return {
+    kind: 'series',
+    series: seriesDefinitions.map(({ signal, errors, ...series }) => ({
+      ...series,
+      data: {
+        kind: 'points',
+        points: createPoints(signal, noise, errors),
+      },
+    })),
+  }
+}