Published
Edited
Feb 24, 2021
{
const output = [];
let state = {
n: 3,
results: []
};
for (var i = 0; i < 4; ++i) {
nativeJavaScript(state);
output.push(state.results[i + 2]);
}
// Change state structure
function nativeJavaScript(state) {
const n = state.n;
state.results[0] = 1 / 6; // B1
state.results[1] = -1 / 30; // B3
let k = n - 2;
let denom = 2;
let accumulatingFraction = (2 * n) / denom; // i.e. 2n / 2, to keep it authentic
let accumulatingTotal = 0;
// Manually process the first 2 terms
accumulatingTotal += -(2 * n - 1) / (2 * n + 1) / 2; // '#4 and #5' - A0
accumulatingTotal += accumulatingFraction * state.results[0]; // A1
let numerator = 2 * n;
let indexToResult = 1;
do {
accumulatingFraction *= (numerator - 1) / (denom + 1); // first terms of A : (2n-1)/3
accumulatingFraction *= (numerator - 2) / (denom + 2); // #19 second 2n+1/4
accumulatingTotal += accumulatingFraction * state.results[indexToResult]; // #21 A3 * B3
numerator -= 2;
denom += 2;
++indexToResult;
} while (--k > 0);
state.results[indexToResult] = -accumulatingTotal;
state.n++;
}
return output;
}
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
