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11811dc | 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 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 | 'use strict';
const t = require('tape');
const random = require('gauss-random')
const bitsf64 = require('math-float64-from-bits')
// const f64bits = require('math-float64-bits')
t('packing 1e6 array', t => {
let y = new Float64Array(1e6)
console.time(1)
y.subarray(0e5, 1e5)
y.subarray(1e5, 2e5)
y.subarray(2e5, 3e5)
y.subarray(3e5, 4e5)
y.subarray(4e5, 5e5)
y.subarray(5e5, 6e5)
y.subarray(6e5, 7e5)
y.subarray(7e5, 8e5)
y.subarray(8e5, 9e5)
console.timeEnd(1)
t.end()
})
t('float64 packing', t => {
// uint8 (level) + uint32 (id) + float32→normalized uint16 (x)
let f64 = new Float64Array(1)
let ui32 = new Uint32Array(f64.buffer)
// view.setUint8(7, parseInt('10000000', 2))
// view.setUint8(6, parseInt('00000000', 2))
// ui8[7] = 0xff
// ui16[2] = 0x1000
ui32[1] = 0x00ff0000 & 0x01 << 16 | 0x0000ffff & 0xffff
console.log(f64[0] /* , f64bits(f64[0]) */)
let sign = '0' // ignore sign
let exp = '00000000000' // write levels as exponent
let fract = '0000000000000000000000000000000000000000000000000000'
console.log(bitsf64(sign + exp + fract))
// 4 '0100000000010000000000000000000000000000000000000000000000000000'
// -0 '1000000000000000000000000000000000000000000000000000000000000000'
// NaN '0111111111111000000000000000000000000000000000000000000000000000'
// +Inf '0111111111110000000000000000000000000000000000000000000000000000'
// -Inf '1111111111110000000000000000000000000000000000000000000000000000'
})
t('sorting comparison', t => {
let N = 1e6
let f64 = data(new Float64Array(N))
console.time(1)
f64.sort()
console.timeEnd(1)
let f32 = data(new Float32Array(N))
console.time(2)
f32.sort()
console.timeEnd(2)
let i32 = data(new Uint32Array(N), i => Math.random() * 0xffffffff)
console.time(3)
i32.sort()
console.timeEnd(3)
let i32b = data(new Uint32Array(N), i => Math.random() * 0xffffffff)
console.time(4)
i32b.sort((a, b) => a - b)
console.timeEnd(4)
let points = data(new Float64Array(N))
let levels = new Uint32Array(N)
let weights = new Uint32Array(N)
let ids = new Uint32Array(N)
let level = 0, i = 0
while (i < N) {
let amt = Math.floor(Math.random() * (N / 16))
let end = Math.min(i + amt, N)
for (; i < end; i++) {
levels[i] = level
ids[i] = i
}
level++
}
const snapSort = require('snap-points-2d/lib/sort')
console.time('snapsort')
snapSort(levels, points, ids, weights, N)
console.timeEnd('snapsort')
})
function data(N=1e6, f) {
let points
if (N.length) {
points = N
}
else {
points = Array(N)
}
for (let i = 0; i < points.length; i++) {
points[i] = f ? f(i) : random()
}
return points
}
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