/**
* @file statistics.cjs
* @description JavaScript bindings for WASM statistical operations
*/
const fs = require('fs');
const path = require('path');
let wasmInstance = null;
let wasmMemory = null;
let memoryOffset = 1024;
async function init() {
const wasmPath = path.join(__dirname, '../build/release.wasm');
const wasmBuffer = fs.readFileSync(wasmPath);
const wasmModule = await WebAssembly.instantiate(wasmBuffer, {
env: {
abort: () => { throw new Error('WASM abort'); }
}
});
wasmInstance = wasmModule.instance;
wasmMemory = wasmInstance.exports.memory;
wasmMemory.grow(256);
}
function allocateF64Array(data) {
const byteLength = data.length * 8;
const ptr = (memoryOffset + 7) & ~7;
memoryOffset = ptr + byteLength;
const pagesNeeded = Math.ceil(memoryOffset / 65536);
const currentPages = wasmMemory.buffer.byteLength / 65536;
if (pagesNeeded > currentPages) {
wasmMemory.grow(pagesNeeded - currentPages);
}
const view = new Float64Array(wasmMemory.buffer, ptr, data.length);
view.set(data);
return ptr;
}
function resetMemory() {
memoryOffset = 1024;
}
function mean(arr) {
resetMemory();
const ptr = allocateF64Array(arr);
return wasmInstance.exports.meanRaw(ptr, arr.length);
}
function variance(arr, normalization = 'unbiased') {
resetMemory();
const ptr = allocateF64Array(arr);
const norm = normalization === 'unbiased' ? 0 : 1;
return wasmInstance.exports.varianceRaw(ptr, arr.length, norm);
}
function std(arr, normalization = 'unbiased') {
resetMemory();
const ptr = allocateF64Array(arr);
const norm = normalization === 'unbiased' ? 0 : 1;
return wasmInstance.exports.stdRaw(ptr, arr.length, norm);
}
function min(arr) {
resetMemory();
const ptr = allocateF64Array(arr);
return wasmInstance.exports.minRaw(ptr, arr.length);
}
function max(arr) {
resetMemory();
const ptr = allocateF64Array(arr);
return wasmInstance.exports.maxRaw(ptr, arr.length);
}
function median(arr) {
resetMemory();
// Make a copy since median modifies the array
const copy = arr.slice();
const ptr = allocateF64Array(copy);
return wasmInstance.exports.medianRaw(ptr, copy.length);
}
function sum(arr) {
resetMemory();
const ptr = allocateF64Array(arr);
return wasmInstance.exports.sumRaw(ptr, arr.length);
}
function product(arr) {
resetMemory();
const ptr = allocateF64Array(arr);
return wasmInstance.exports.productRaw(ptr, arr.length);
}
function mode(arr) {
resetMemory();
// Make a copy since mode modifies the array (uses quicksort)
const copy = arr.slice();
const ptr = allocateF64Array(copy);
return wasmInstance.exports.modeRaw(ptr, copy.length);
}
module.exports = {
init,
mean,
variance,
std,
min,
max,
median,
sum,
product,
mode
};
