Spaces:
Build error
Build error
File size: 1,600 Bytes
c211499 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 |
// https://github.com/python/cpython/blob/a74eea238f5baba15797e2e8b570d153bc8690a7/Modules/mathmodule.c#L1423
export class Adder {
constructor() {
this._partials = new Float64Array(32);
this._n = 0;
}
add(x) {
const p = this._partials;
let i = 0;
for (let j = 0; j < this._n && j < 32; j++) {
const y = p[j],
hi = x + y,
lo = Math.abs(x) < Math.abs(y) ? x - (hi - y) : y - (hi - x);
if (lo) p[i++] = lo;
x = hi;
}
p[i] = x;
this._n = i + 1;
return this;
}
valueOf() {
const p = this._partials;
let n = this._n, x, y, lo, hi = 0;
if (n > 0) {
hi = p[--n];
while (n > 0) {
x = hi;
y = p[--n];
hi = x + y;
lo = y - (hi - x);
if (lo) break;
}
if (n > 0 && ((lo < 0 && p[n - 1] < 0) || (lo > 0 && p[n - 1] > 0))) {
y = lo * 2;
x = hi + y;
if (y == x - hi) hi = x;
}
}
return hi;
}
}
export function fsum(values, valueof) {
const adder = new Adder();
if (valueof === undefined) {
for (let value of values) {
if (value = +value) {
adder.add(value);
}
}
} else {
let index = -1;
for (let value of values) {
if (value = +valueof(value, ++index, values)) {
adder.add(value);
}
}
}
return +adder;
}
export function fcumsum(values, valueof) {
const adder = new Adder();
let index = -1;
return Float64Array.from(values, valueof === undefined
? v => adder.add(+v || 0)
: v => adder.add(+valueof(v, ++index, values) || 0)
);
}
|