view fft/test.js @ 5:b4ab69bdb4c8

Beginnings of an emscripten example

/* for a phase vocoder, we probably want 2048-point real-to-complex
 * FFTs (if available) */

function inputReals(size) {
    var result = new Array(size);
    for (var i = 0; i < result.length; i++)
	result[i] = (i % 20) / 10.0 - 1.0;
    return result;
}

function zeroReals(size) {
    var result = new Array(size);
    for (var i = 0; i < result.length; i++)
	result[i] = 0.0;
    return result;
}

function inputReal64s(size) {
    var result = new Float64Array(size);
    for (var i = 0; i < result.length; i++)
	result[i] = (i % 20) / 10.0 - 1.0;
    return result;
}

function inputComplexArray(size) {
    var result = new complex_array.ComplexArray(size);
    for (var i = 0; i < size; i++) {
	result.real[i] = (i % 20) / 10.0 - 1.0;
	result.imag[i] = 0.0;
    }
    return result;
}

var iterations = 2150;
var size = 2048;

function report(name, start, middle, end, total) {
    document.getElementById(name + "-result").innerHTML = total;
    document.getElementById(name + "-1").innerHTML =
	Math.round(middle - start) + " ms";
    document.getElementById(name + "-2").innerHTML =
	Math.round(end - middle) + " ms";
    document.getElementById(name + "-itr").innerHTML =
	Math.round((1000.0 / ((end - middle) / iterations))) + " itr/sec";
}

function testNayuki() {

    var start = performance.now();
    var middle = start;
    var end = start;

    var total = 0.0;

    for (var i = 0; i < 2*iterations; ++i) {
	if (i == iterations) {
	    middle = performance.now();
	}
	var real = inputReals(size);
	var imag = zeroReals(size);
	transform(real, imag);
	for (var j = 0; j < size; ++j) {
	    total += Math.sqrt(real[j] * real[j] + imag[j] * imag[j]);
	}
    }

    var end = performance.now();

    report("nayuki", start, middle, end, total);
}

function testNockert() {
    
    var fft = new FFT.complex(size, false);
    
    var start = performance.now();
    var middle = start;
    var end = start;

    total = 0.0;

    for (var i = 0; i < 2*iterations; ++i) {
	if (i == iterations) {
	    middle = performance.now();
	}
	var ri = inputReal64s(size);
	var co = new Float64Array(2 * size);
	fft.simple(co, ri, 'real');
	for (var j = 0; j < size; ++j) {
	    total += Math.sqrt(co[j*2] * co[j*2] + co[j*2+1] * co[j*2+1]);
	}
    }

    var end = performance.now();

    report("nockert", start, middle, end, total);
}

function testDntj() {

    var start = performance.now();
    var middle = start;
    var end = start;

    total = 0.0;
    var scale = Math.sqrt(size);

    for (var i = 0; i < 2*iterations; ++i) {
	if (i == iterations) {
	    middle = performance.now();
	}
	var ci = inputComplexArray(size);
	var co = ci.FFT();
	for (var j = 0; j < size; ++j) {
	    total += scale *
		Math.sqrt(co.real[j] * co.real[j] + co.imag[j] * co.imag[j]);
	}
    }

    var end = performance.now();

    report("dntj", start, middle, end, total);
}

function test() {

    document.getElementById("test-description").innerHTML =
	"For " + iterations + " iterations per half (" + 2*iterations
	+ " total) of size " + size;

    testNayuki();
    testNockert();
    testDntj();
}

window.onload = test;