Chris@3: 
Chris@3: /* for a phase vocoder, we probably want 2048-point real-to-complex
Chris@3:  * FFTs (if available) */
Chris@3: 
Chris@3: function inputReals(size) {
Chris@8:     var result = new Float32Array(size);
Chris@3:     for (var i = 0; i < result.length; i++)
Chris@3: 	result[i] = (i % 20) / 10.0 - 1.0;
Chris@3:     return result;
Chris@3: }
Chris@3: 
Chris@3: function zeroReals(size) {
Chris@8:     var result = new Float32Array(size);
Chris@3:     for (var i = 0; i < result.length; i++)
Chris@3: 	result[i] = 0.0;
Chris@3:     return result;
Chris@3: }
Chris@3: 
Chris@3: function inputReal64s(size) {
Chris@3:     var result = new Float64Array(size);
Chris@3:     for (var i = 0; i < result.length; i++)
Chris@3: 	result[i] = (i % 20) / 10.0 - 1.0;
Chris@3:     return result;
Chris@3: }
Chris@3: 
Chris@7: function zeroReal64s(size) {
Chris@7:     var result = new Float64Array(size);
Chris@7:     for (var i = 0; i < result.length; i++)
Chris@7: 	result[i] = (i % 20) / 10.0 - 1.0;
Chris@7:     return result;
Chris@7: }
Chris@7: 
Chris@3: function inputComplexArray(size) {
Chris@3:     var result = new complex_array.ComplexArray(size);
Chris@3:     for (var i = 0; i < size; i++) {
Chris@3: 	result.real[i] = (i % 20) / 10.0 - 1.0;
Chris@3: 	result.imag[i] = 0.0;
Chris@3:     }
Chris@3:     return result;
Chris@3: }
Chris@3: 
Chris@3: var iterations = 2150;
Chris@3: var size = 2048;
Chris@3: 
Chris@3: function report(name, start, middle, end, total) {
Chris@3:     document.getElementById(name + "-result").innerHTML = total;
Chris@3:     document.getElementById(name + "-1").innerHTML =
Chris@3: 	Math.round(middle - start) + " ms";
Chris@3:     document.getElementById(name + "-2").innerHTML =
Chris@3: 	Math.round(end - middle) + " ms";
Chris@3:     document.getElementById(name + "-itr").innerHTML =
Chris@3: 	Math.round((1000.0 / ((end - middle) / iterations))) + " itr/sec";
Chris@3: }
Chris@3: 
Chris@3: function testNayuki() {
Chris@3: 
Chris@3:     var start = performance.now();
Chris@3:     var middle = start;
Chris@3:     var end = start;
Chris@3: 
Chris@3:     var total = 0.0;
Chris@3: 
Chris@3:     for (var i = 0; i < 2*iterations; ++i) {
Chris@3: 	if (i == iterations) {
Chris@3: 	    middle = performance.now();
Chris@3: 	}
Chris@3: 	var real = inputReals(size);
Chris@3: 	var imag = zeroReals(size);
Chris@3: 	transform(real, imag);
Chris@3: 	for (var j = 0; j < size; ++j) {
Chris@4: 	    total += Math.sqrt(real[j] * real[j] + imag[j] * imag[j]);
Chris@3: 	}
Chris@3:     }
Chris@3: 
Chris@3:     var end = performance.now();
Chris@3: 
Chris@3:     report("nayuki", start, middle, end, total);
Chris@3: }
Chris@3: 
Chris@3: function testNockert() {
Chris@3:     
Chris@3:     var fft = new FFT.complex(size, false);
Chris@3:     
Chris@3:     var start = performance.now();
Chris@3:     var middle = start;
Chris@3:     var end = start;
Chris@3: 
Chris@3:     total = 0.0;
Chris@3: 
Chris@3:     for (var i = 0; i < 2*iterations; ++i) {
Chris@3: 	if (i == iterations) {
Chris@3: 	    middle = performance.now();
Chris@3: 	}
Chris@3: 	var ri = inputReal64s(size);
Chris@3: 	var co = new Float64Array(2 * size);
Chris@3: 	fft.simple(co, ri, 'real');
Chris@4: 	for (var j = 0; j < size; ++j) {
Chris@4: 	    total += Math.sqrt(co[j*2] * co[j*2] + co[j*2+1] * co[j*2+1]);
Chris@3: 	}
Chris@3:     }
Chris@3: 
Chris@3:     var end = performance.now();
Chris@3: 
Chris@3:     report("nockert", start, middle, end, total);
Chris@3: }
Chris@3: 
Chris@3: function testDntj() {
Chris@3: 
Chris@3:     var start = performance.now();
Chris@3:     var middle = start;
Chris@3:     var end = start;
Chris@3: 
Chris@3:     total = 0.0;
Chris@4:     var scale = Math.sqrt(size);
Chris@3: 
Chris@3:     for (var i = 0; i < 2*iterations; ++i) {
Chris@3: 	if (i == iterations) {
Chris@3: 	    middle = performance.now();
Chris@3: 	}
Chris@3: 	var ci = inputComplexArray(size);
Chris@3: 	var co = ci.FFT();
Chris@3: 	for (var j = 0; j < size; ++j) {
Chris@4: 	    total += scale *
Chris@4: 		Math.sqrt(co.real[j] * co.real[j] + co.imag[j] * co.imag[j]);
Chris@3: 	}
Chris@3:     }
Chris@3: 
Chris@3:     var end = performance.now();
Chris@3: 
Chris@4:     report("dntj", start, middle, end, total);
Chris@3: }
Chris@3: 
Chris@7: function testCross() {
Chris@7: 
Chris@7:     var fft = new FFTCross(size);
Chris@7:     
Chris@7:     var start = performance.now();
Chris@7:     var middle = start;
Chris@7:     var end = start;
Chris@7: 
Chris@7:     total = 0.0;
Chris@7: 
Chris@7:     for (var i = 0; i < 2*iterations; ++i) {
Chris@7: 	if (i == iterations) {
Chris@7: 	    middle = performance.now();
Chris@7: 	}
Chris@7: 	var ri = inputReal64s(size);
Chris@7: 	var out = fft.transformReal(ri, false);
Chris@7: 	for (var j = 0; j < size; ++j) {
Chris@7: 	    total += 
Chris@7: 		Math.sqrt(out.real[j] * out.real[j] + out.imag[j] * out.imag[j]);
Chris@7: 	}
Chris@7:     }
Chris@7: 
Chris@7:     var end = performance.now();
Chris@8:     
Chris@8:     report("cross", start, middle, end, total);
Chris@7: 
Chris@8:     fft.discard();
Chris@8: }
Chris@8: 
Chris@8: function testKissFFT() {
Chris@8: 
Chris@8:     var fft = new KissFFT(size);
Chris@8:     
Chris@8:     var start = performance.now();
Chris@8:     var middle = start;
Chris@8:     var end = start;
Chris@8: 
Chris@8:     total = 0.0;
Chris@8: 
Chris@8:     for (var i = 0; i < 2*iterations; ++i) {
Chris@8: 	if (i == iterations) {
Chris@8: 	    middle = performance.now();
Chris@8: 	}
Chris@8: 	var ri = inputReals(size);
Chris@8: 	var out = fft.forward(ri);
Chris@8: 	for (var j = 0; j <= size/2; ++j) {
Chris@8: 	    total += Math.sqrt(out[j*2] * out[j*2] + out[j*2+1] * out[j*2+1]);
Chris@8: 	}
Chris@8: 	// KissFFT returns only the first half of the output (plus
Chris@8: 	// DC/Nyquist) -- synthesise the conjugate half
Chris@8: 	for (var j = 1; j < size/2; ++j) {
Chris@8: 	    total += Math.sqrt(out[j*2] * out[j*2] + out[j*2+1] * out[j*2+1]);
Chris@8: 	}
Chris@8:     }
Chris@8: 
Chris@8:     var end = performance.now();
Chris@8:     
Chris@8:     report("kissfft", start, middle, end, total);
Chris@8: 
Chris@8:     fft.discard();
Chris@7: }
Chris@7: 
Chris@3: function test() {
Chris@3: 
Chris@3:     document.getElementById("test-description").innerHTML =
Chris@8: 	"Running " + 2*iterations + " iterations of FFT size " + size + ".<br>Timings are given separately for the first half of the run (" + iterations + " iterations) and the second half, in case the JS engine takes some warming up."
Chris@3: 
Chris@3:     testNayuki();
Chris@3:     testNockert();
Chris@3:     testDntj();
Chris@7:     testCross();
Chris@8:     testKissFFT();
Chris@3: }
Chris@3: 
Chris@3: window.onload = test;
Chris@3: