card_back.html

{{Front}}

<p id="youSaid"><i class="hint">You said: </i><span id="intervalTextDisplay"></span></p>

<hr style="opacity:0.3" id="answer">

<p><i class="hint">Answer:</i> {{Answer (must be a number)}}</p>

<p class="hint">{{Notes}}</p>

<div id="errorContainer">
	<p id="error" style="color:red"></p>
</div>

<p id="intervalResults"></p>

<p id="accuracyDisplay" class="hint intervalBack" style="font-size: small;">Desired accuracy multiplier: <span id="accuracySpan"></span></p>

<div class="intervalBack" style="position: absolute; left: 50%; transform: translateX(-50%); bottom: 5px; background: grey; padding: 0 20px; display: flex; font-weight: bold" title="Based on your score, we recommend you select this difficulty. Get a higher score to see this card less often.">
	<p id="buttonHint"></p>
</div>


<script>
	function setError(errStr) {
		document.querySelector("#error").textContent = errStr
	}

	document.querySelector("#intervalTextDisplay").textContent = window.INTERVAL_TEXT
	
	if (!window.INTERVAL_TEXT) {
		setError("You didn't type an answer")
		document.querySelector("#youSaid").style = "display: none"
  	document.querySelectorAll(".intervalBack").forEach((el) => el.style = "display:none")
	} else {

		var interval = window.INTERVAL_TEXT
		
		var parts = interval.split("-").map(part => part.trim())

		var accuracyMultiplier = String.raw`{{Desired accuracy multiplier}}` || "1"
		
		if (parts.length === 2) {
			if (isNaN(String.raw`{{Answer (must be a number)}}`)) {
				setError("Error: card back is not numerical: {{Answer (must be a number)}}")
			}
			else if (isNaN(parts[0])) {
				setError("Error: lower bound is not numerical: " + parts[0])
			} else if (isNaN(parts[1])) {
				setError("Error: upper bound is not numerical: " + parts[1])
			} else if (!CONFIDENCE_INTERVAL) {
				setError("Plugin error: missing confidence interval")
			} else if (isNaN(accuracyMultiplier) || accuracyMultiplier <= 0) {
				setError("Error: desired accuracy multiplier must be a positive number. 1 = default, 2 = high accuracy, 0.5 = low accuracy.")
			} else {
				var lower = Number(parts[0])
				var upper = Number(parts[1])
				var answer = Number(String.raw`{{Answer (must be a number)}}`)

				var results = document.querySelector("#intervalResults")

				var correct = answer >= lower && answer <= upper
				if (correct) {
					results.textContent = "✅ Correct!"
					results.style = "background: darkgreen; padding: 5px"
				} else {
					results.textContent = "🔴 Incorrect!"
					results.style = "background: darkred; padding: 5px"
				}
	
				var useLogScoring = answer >= 10000
				var score = ankiScore(lower, upper, answer, window.CONFIDENCE_INTERVAL, useLogScoring, 1000)
				results.textContent += ` ${score > 0 ? "+" : ""}${score.toPrecision(2)} points`

				if (accuracyMultiplier == 1) {
					document.querySelector("#accuracyDisplay").style = "display:none"
				} else {
					document.querySelector("#accuracySpan").textContent = accuracyMultiplier
				}

				var recommendation = score < 0 ? "Again [1]" : ( score < (2 * accuracyMultiplier) ? "Hard [2]" : ( score < (4 * accuracyMultiplier) ? "Good [3]" : "Easy [4]" ) )
				document.querySelector("#buttonHint").textContent = `${recommendation}`

				var calibrationData = {
					correct,
					confidenceInterval: window.CONFIDENCE_INTERVAL,
					score,
					timestamp: new Date(),
					question: String.raw`{{Front}}`.replace("\n", ""),
				}
				window.bridgeCommand(`updateCalibration;${JSON.stringify(calibrationData)}`)
			}

		} else {
			document.querySelectorAll(".intervalBack").forEach((el) => el.style = "display:none")
		}

	}


function ankiScore(
  lowerBound,
  upperBound,
  answer,
  confidenceInterval,
  useLogScoring,
  C,
) {
  const SMAX = 10;
  const SMIN = -50; // higher lower bound for challenge questions to be more forgiving
  const DELTA = 0.4;
  const EPSILON = 0.0000000001;
  const B = confidenceInterval / 100;

  return greenbergScoring(lowerBound,
    upperBound,
    answer,
    useLogScoring,
    C,
    SMAX,
    SMIN,
    DELTA,
    EPSILON,
    B,
  )
}

function greenbergScoring(
  lowerBound,
  upperBound,
  answer,
  useLogScoring,
  C,
  SMAX,
  SMIN,
  DELTA,
  EPSILON,
  B,
) {
  if (!useLogScoring) {
    lowerBound -= EPSILON;
    upperBound += EPSILON;
    let r = (lowerBound - answer) / C;
    let s = (upperBound - lowerBound) / C;
    let t = (answer - upperBound) / C;
    if (answer < lowerBound) {
      return Math.max(SMIN, (-2 / (1 - B)) * r - (r / (1 + r)) * s);
    } else if (answer > upperBound) {
      return Math.max(SMIN, (-2 / (1 - B)) * t - (t / (1 + t)) * s);
    }
    lowerBound -= DELTA;
    upperBound += DELTA;
    r = (lowerBound - answer) / C;
    s = (upperBound - lowerBound) / C;
    t = (answer - upperBound) / C;
    return ((4 * SMAX * r * t) / (s * s)) * (1 - s / (1 + s));
  } else {
    lowerBound /= 10 ** EPSILON;
    upperBound *= 10 ** EPSILON;
    let r = Math.log(lowerBound / answer) / Math.log(C);
    let s = Math.log(upperBound / lowerBound) / Math.log(C);
    let t = Math.log(answer / upperBound) / Math.log(C);
    if (answer < lowerBound) {
      return Math.max(SMIN, (-2 / (1 - B)) * r - (r / (1 + r)) * s);
    } else if (answer > upperBound) {
      return Math.max(SMIN, (-2 / (1 - B)) * t - (t / (1 + t)) * s);
    }
    lowerBound /= 10 ** DELTA;
    upperBound *= 10 ** DELTA;
    r = Math.log(lowerBound / answer) / Math.log(C);
    s = Math.log(upperBound / lowerBound) / Math.log(C);
    t = Math.log(answer / upperBound) / Math.log(C);
    return ((4 * SMAX * r * t) / (s * s)) * (1 - s / (1 + s));
  }
};

</script>