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@cag
Created December 13, 2019 21:53
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LMSR Bid/Ask Chart
<!DOCTYPE html>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
<title>LMSR Bid/Ask Chart</title>
<main style="max-width: 960px; margin: auto;">
<h1>LMSR Bid/Ask Chart</h1>
<form>
<ul>
<li>
<label for="num-outcomes"># Outcomes:</label>
<input type="number" id="num-outcomes" value="2" min="2" step="1">
</li>
<li>
<label for="funding">Funding:</label>
<input type="number" id="funding" value="1000">
</li>
<li>
<label for="odds">Est. Odds for Outcome:</label>
<input type="range" id="odds" min="0.01" max=".99" step="0.01" value="0.5">
<output id="odds-display"></output>
</li>
</ul>
</form>
<canvas id="my-chart"></canvas>
</main>
<script src="https://cdn.jsdelivr.net/npm/chart.js@2.9.3/dist/Chart.min.js" integrity="sha256-R4pqcOYV8lt7snxMQO/HSbVCFRPMdrhAFMH+vr9giYI=" crossorigin="anonymous"></script>
<script>
// Credit David Walsh (https://davidwalsh.name/javascript-debounce-function)
// Returns a function, that, as long as it continues to be invoked, will not
// be triggered. The function will be called after it stops being called for
// N milliseconds. If `immediate` is passed, trigger the function on the
// leading edge, instead of the trailing.
function debounce(func, wait, immediate) {
let timeout;
return function executedFunction() {
const args = arguments;
const later = () => {
timeout = null;
if (!immediate) func.apply(this, args);
};
const callNow = immediate && !timeout;
clearTimeout(timeout);
timeout = setTimeout(later, wait);
if (callNow) func.apply(this, args);
};
};
const numOutcomesInput = document.querySelector('#num-outcomes')
const fundingInput = document.querySelector('#funding')
const oddsInput = document.querySelector('#odds')
const buyData = new Array(100)
const sellData = new Array(100)
function refreshData() {
const numOutcomes = parseInt(numOutcomesInput.value)
const funding = parseFloat(fundingInput.value)
const odds = parseFloat(oddsInput.value)
const priceForAmount = (amount) =>
funding * Math.log(
(Math.pow(numOutcomes, amount / funding) - 1) * odds + 1
) /
(amount * Math.log(numOutcomes))
for (let i = 0; i < buyData.length; i++) {
const y = i * funding / 10
if(i === 0) {
buyData[i] = { x: odds, y: 0 }
sellData[i] = { x: odds, y: 0 }
} else {
buyData[i] = { x: priceForAmount(-y), y }
sellData[i] = { x: priceForAmount(y), y }
}
}
}
refreshData()
const ctx = document.getElementById('my-chart').getContext('2d');
console.log(buyData[2], sellData[2])
const myChart = new Chart(ctx, {
type: 'line',
data: {
datasets: [{
label: "MM's BID",
fill: false,
borderColor: 'rgb(132, 255, 99)',
data: buyData,
}, {
label: "MM's ASK",
fill: false,
borderColor: 'rgb(255, 99, 132)',
data: sellData,
}]
},
options: {
elements: {
line: {
tension: 0
}
},
scales: {
xAxes: [{
scaleLabel: {
display: true,
labelString: 'Average OT price',
},
type: 'linear',
ticks: {
min: 0,
max: 1,
}
}],
yAxes: [{
scaleLabel: {
display: true,
labelString: 'OT Quantity',
},
type: 'linear',
ticks: {
min: 0,
}
}],
}
}
});
const oddsDisplay = document.querySelector('#odds-display')
oddsDisplay.textContent = (oddsInput.value * 100).toFixed(0) + '%'
const updateGraph = debounce(() => {
refreshData()
myChart.update()
}, 200);
numOutcomesInput.oninput = updateGraph
fundingInput.oninput = updateGraph
oddsInput.oninput = function() {
oddsDisplay.textContent = (oddsInput.value * 100).toFixed(0) + '%'
updateGraph()
}
</script>
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