Function switchTimeframe

examples/candlestick-streaming/main.ts:266–347

* Switch to a different candlestick timeframe. * Regenerates historical data and recreates the candle aggregator.

(tf: string)

 * Regenerates historical data and recreates the candle aggregator.
 */
function switchTimeframe(tf: string) {
  if (!TIMEFRAME_INTERVALS[tf]) {
    console.warn(`Unknown timeframe: ${tf}`);
    return;
  }

  // Skip if already on this timeframe
  if (tf === currentTimeframe) {
    return;
  }

  // Remember if we were streaming
  const wasStreaming = isStreaming;

  // Stop streaming while we regenerate
  if (isStreaming) {
    tickSimulator.stop();
  }

  // Update timeframe state
  currentTimeframe = tf;
  candleIntervalMs = TIMEFRAME_INTERVALS[tf];
  timeScale = TIMEFRAME_TIMESCALES[tf];

  console.log(`Switching to ${tf} timeframe (${candleIntervalMs}ms interval, ${timeScale}x speed)`);

  // Regenerate historical data with new interval
  const startGen = performance.now();
  data = generateHistoricalData({
    symbol: CONFIG.symbol,
    startPrice: CONFIG.startPrice,
    volatility: 0.03, // 3% volatility like static example for nice candle sizes
    candleCount: currentCandleCount,
    intervalMs: candleIntervalMs,
  });
  console.log(`Regenerated ${data.length.toLocaleString()} candles in ${(performance.now() - startGen).toFixed(0)}ms`);

  // Get last price for tick simulator
  const lastCandle = data[data.length - 1];
  const lastPrice = getClose(lastCandle);

  // Reset simulated time based on new data
  simulatedTimeMs = getTimestamp(lastCandle) + candleIntervalMs;
  lastSimPerfNow = performance.now();

  // Recreate candle aggregator with new interval
  candleAggregator = createCandleAggregator(candleIntervalMs);

  // Recreate tick simulator with current price
  tickSimulator = createTickSimulator({
    initialPrice: lastPrice,
    ticksPerSecond: CONFIG.ticksPerSecond,
    volatility: CONFIG.tickVolatility,
    onTick: handleTick,
  });

  // Update chart with new data (full replacement)
  const series0 = fullChartOptions.series?.[0];