50ohm-contents-dl/contents/html/quantisierung_und_sampling.html

<script src="https://www.50ohm.de/assets/chartjs/4.4.1/chart.min.js"></script>

<style>
  .sq-applet {
    width: 100%;
    max-width: 100%;
    min-width: 0;
    box-sizing: border-box;
    display: grid;
    gap: .8rem;
    font-size: 15px;
    container-type: inline-size;
  }

  .sq-applet .sq-controls {
    display: grid;
    grid-template-columns: minmax(9.5em, 1.2fr) minmax(8em, 2fr) minmax(7.5em, auto);
    gap: .55rem .8rem;
    align-items: center;
    min-width: 0;
  }

  .sq-applet label,
  .sq-applet output {
    margin: 0;
    line-height: 1.2;
    white-space: nowrap;
  }

  .sq-applet label {
    font-weight: 600;
  }

  .sq-applet input[type="range"] {
    display: block;
    width: 100%;
    min-width: 0;
    margin: 0;
  }

  .sq-applet output {
    display: block;
    min-width: 7.5em;
    text-align: left;
    font-variant-numeric: tabular-nums;
  }

  .sq-applet .sq-chart-wrap {
    position: relative;
    width: 100%;
    height: clamp(220px, 43cqw, 360px);
    min-width: 0;
    min-height: 0;
  }

  .sq-applet canvas {
    position: absolute;
    inset: 0;
    display: block;
    width: 100% !important;
    height: 100% !important;
  }

  @container (max-width: 520px) {
    .sq-applet .sq-controls {
      grid-template-columns: minmax(7.5em, auto) minmax(6em, 1fr) 6.8em;
      gap: .45rem .55rem;
    }

    .sq-applet output {
      min-width: 6.8em;
    }
  }
</style>

<div class="sq-applet" aria-label="Prova sampling och kvantisering">
  <div class="sq-controls">
    <label>Tidssampling:</label>
    <input data-sq-time type="range" value="4" min="1" max="10" step="1" aria-label="Samplingfrekvens">
    <output data-sq-time-output>16 sampel/s</output>

    <label>Värdekvantisering:</label>
    <input data-sq-value type="range" value="16" min="1" max="16" step="1" aria-label="Kvantiseringsbitar">
    <output data-sq-value-output>16 bit</output>
  </div>

  <div class="sq-chart-wrap">
    <canvas data-sq-chart aria-label="Tidskontinuerlig samt tids- och värdediskret signal"></canvas>
  </div>

  <script>
    (function () {
      const applet = document.currentScript.closest('.sq-applet');
      const timeInput = applet.querySelector('[data-sq-time]');
      const valueInput = applet.querySelector('[data-sq-value]');
      const timeOutput = applet.querySelector('[data-sq-time-output]');
      const valueOutput = applet.querySelector('[data-sq-value-output]');
      const canvas = applet.querySelector('[data-sq-chart]');
      const amplitude = 100;
      const duration = 1;

      const chart = new Chart(canvas, {
        type: 'scatter',
        data: {
          datasets: [
            {
              label: 'Värde- och tidsdiskret signal',
              data: [],
              borderColor: '#00AEDF',
              borderWidth: 2,
              pointRadius: 0,
              showLine: true,
              stepped: true
            },
            {
              label: 'Tidskontinuerlig signal',
              data: [],
              borderColor: '#999999',
              borderWidth: 2,
              pointRadius: 0,
              showLine: true,
              tension: .1
            }
          ]
        },
        options: {
          animation: false,
          responsive: true,
          maintainAspectRatio: false,
          interaction: { mode: null },
          plugins: {
            legend: {
              position: 'top',
              labels: {
                boxWidth: 28,
                boxHeight: 10,
                padding: 12,
                font: { size: 12 }
              }
            }
          },
          scales: {
            y: {
              min: -120,
              max: 120,
              ticks: {
                maxTicksLimit: 5,
                callback: function (value) { return value + '%'; }
              }
            },
            x: {
              min: 0,
              max: duration,
              title: { display: true, text: 'Tid' },
              ticks: {
                stepSize: 1,
                callback: function (value) { return value + ' s'; }
              }
            }
          }
        }
      });

      function update() {
        const samples = Math.pow(2, Number(timeInput.value));
        const bits = Number(valueInput.value);
        const levels = Math.pow(2, bits);
        const sampleDistance = duration / samples;
        const quantizationStep = 2 * amplitude / levels;
        const continuous = [];
        const quantized = [];

        for (let x = 0; x <= duration + 1e-9; x += 1 / 128) {
          continuous.push({ x: x, y: amplitude * Math.sin(2 * Math.PI * x) });
        }

        for (let x = 0; x <= duration + 1e-9; x += sampleDistance) {
          const value = amplitude * Math.sin(2 * Math.PI * x);
          const quantizedValue = Math.max(
            -amplitude,
            Math.min(amplitude, Math.sign(value) * quantizationStep * Math.floor(Math.abs(value) / quantizationStep + 1))
          );
          quantized.push({ x: x, y: quantizedValue });
        }

        chart.data.datasets[0].data = quantized;
        chart.data.datasets[1].data = continuous;
        chart.update('none');
        timeOutput.textContent = samples + ' sampel/s';
        valueOutput.textContent = bits + ' bit';
      }

      timeInput.addEventListener('input', update);
      valueInput.addEventListener('input', update);
      update();
    }());
  </script>
</div>