Over 2 decades of experience on the Web…
buffer = {
try {
const stream = await data.file(label).stream();
const reader = stream.getReader();
let done, value;
while ((({ done, value } = await reader.read()), !done)) {
yield value;
}
} catch (error) {
return [];
}
}
async function* pipe(
container /* node */,
trickle /* iterable */,
{ amount = 1000, chunk = 5, start = -1 } = {}
) {
let i = start;
container.textContent = "";
for (const n of await trickle) {
container.textContent +=
i < 0
? n + (i === -1 ? ".\n" : "")
: (i && i % chunk === 0 ? " " : "") + n;
yield container.textContent.replace(/\s/g, "").split("");
if (++i === amount) break;
}
}
/*!
* GOTCHA: Avoid defining the spigot functions using shorthand syntax
*/
spigot = ({
/* {{{ Pi: */
pi: function* (n = NaN) {
for (
let p, q, k = 2n, a = 4n, b = 1n, a_ = 12n, b_ = 4n;
isNaN(+n) || n > -1;
k++
) {
[p, q] = [k * k, 2n * k + 1n];
[a, b, a_, b_] = [a_, b_, p * a + q * a_, p * b + q * b_];
for (let d; (d = a / b) === a_ / b_ && (isNaN(+n) || n > -1); n--) {
yield Number(d);
[a, a_] = [10n * (a % b), 10n * (a_ % b_)];
}
/* thank you, Matz! - mg */
}
},
pi_: function* (n = NaN) {
SWEEP: for (
let i = 2n, q = 1n, r = 180n, t = 60n, u, y;
isNaN(+n) || n > -1;
i++, n--
) {
y = (q * (27n * i - 12n) + 5n * r) / (5n * t);
u = 3n * (3n * i + 1n) * (3n * i + 2n);
r = 10n * u * (q * (5n * i - 2n) + r - y * t);
q = 10n * q * i * (2n * i - 1n);
t *= u;
yield Number(y);
}
},
/* }}} */
/* {{{ Napier's constant: */
e: function (digits = 1000) {
const e = [];
SWEEP: for (
let bump = 9,
A = Array.from(Array((digits += bump)), (_, i) =>
!i ? 0 : !(1 - i) ? 2 : 1
),
x = 0;
digits > bump;
) {
for (let n = digits--; --n; ) {
A[n] = x % n;
x = 10 * A[n - 1] + Math.trunc(x / n);
}
e.push(x);
/* thank you, Xavier Gourdon - mg */
}
return (e.shift() + "").split("").map(Number).concat(e);
},
e_: function (digits = 1000) {
const e = [2];
SWEEP: for (
let i = 0,
A = Array(digits + 3).fill(1),
B = Array.from(A, (_, i) => i + 2),
j,
q;
i < digits;
i++
) {
A = Array.from(A, (x) => x * 10);
for (j = A.length - 1; j > -1; --j > -1 && (A[j] += q)) {
q = Math.trunc(A[j] / B[j]);
A[j] = A[j] % B[j];
}
e.push(q);
}
return e;
}
/* }}} */
})
One platform to build and deploy the best data apps
Experiment and prototype by building visualizations in live JavaScript notebooks. Collaborate with your team and decide which concepts to build out.
Use Observable Framework to build data apps locally. Use data loaders to build in any language or library, including Python, SQL, and R.
Seamlessly deploy to Observable. Test before you ship, use automatic deploy-on-commit, and ensure your projects are always up-to-date.