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Manually calculate the square root of a number with Javascript
// The Babylonian Method
// http://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method
// @param n - the number to compute the square root of
// @param g - the best guess so far (can omit from initial call)
function squirt(n, g) {
if (!g) {
// Take an initial guess at the square root
g = n / 2.0;
}
var d = n / g; // Divide our guess into the number
var ng = (d + g) / 2.0; // Use average of g and d as our new guess
if (g == ng) {
// The new guess is the same as the old guess; further guesses
// can get no more accurate so we return this guess
return g;
}
// Recursively solve for closer and closer approximations of the square root
return squirt(n, ng);
}
console.log(squirt(42)); // 6.48074069840786
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