Calculate Pi to Nth Digit

calculate-pi-to-nth-digit.markdown

Calculate Pi to Nth Digit

A Pen by Bennett on CodePen.

License.

index.html

<label for="digits">How many digits of pi do you need? (30 max)</label>
<br />
<input type="number" id="digits">
<br />
<button type="submit" id="submit">Submit</button>
<p id="result"></p>

script.js

/*Return pi to the nth digit using Javascript and JQ

function calculatePi(n) {
  //Input too long or not a number, default to 30
  if (n === undefined || n > 30) {
    n = 30;
  }
  
  //Machin's formula for pi:
  return (16 * Math.atan(1 / 5) - 4 * Math.atan(1 / 239)).toFixed(n);
}

$("#submit").click(function() {
  var digits = $("#digits").val();
  $("#result").html(calculatePi(digits));
});

scripts

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>