Merge util

dy · dy · commit b5fe36b4faa1 · 2026-03-26T00:57:20.000-04:00
diff --git a/_util.js b/_util.js
diff --git a/bartlettHann.js b/bartlettHann.js
@@ -1,4 +1,4 @@
-import { abs, cos, PI2 } from './_util.js'
+import { abs, cos, PI2 } from './util.js'
 export default function bartlettHann (i, N) {
 	let x = i / (N - 1)
 	return 0.62 - 0.48 * abs(x - 0.5) - 0.38 * cos(PI2 * x)
diff --git a/blackman.js b/blackman.js
@@ -1,2 +1,2 @@
-import { cosineSum } from './_util.js'
+import { cosineSum } from './util.js'
 export default function blackman (i, N) { return cosineSum(i, N, [0.42, 0.5, 0.08]) }
diff --git a/blackmanHarris.js b/blackmanHarris.js
@@ -1,2 +1,2 @@
-import { cosineSum } from './_util.js'
+import { cosineSum } from './util.js'
 export default function blackmanHarris (i, N) { return cosineSum(i, N, [0.35875, 0.48829, 0.14128, 0.01168]) }
diff --git a/blackmanNuttall.js b/blackmanNuttall.js
@@ -1,2 +1,2 @@
-import { cosineSum } from './_util.js'
+import { cosineSum } from './util.js'
 export default function blackmanNuttall (i, N) { return cosineSum(i, N, [0.3635819, 0.4891775, 0.1365995, 0.0106411]) }
diff --git a/bohman.js b/bohman.js
@@ -1,4 +1,4 @@
-import { abs, cos, sin, PI } from './_util.js'
+import { abs, cos, sin, PI } from './util.js'
 export default function bohman (i, N) {
 	let a = abs((2 * i - N + 1) / (N - 1))
 	if (a >= 1) return 0
diff --git a/confinedGaussian.js b/confinedGaussian.js
@@ -1,4 +1,4 @@
-import { exp } from './_util.js'
+import { exp } from './util.js'
 export default function confinedGaussian (i, N, sigmaT) {
 	if (sigmaT == null) sigmaT = 0.1
 	let L = N + 1, half = (N - 1) / 2
diff --git a/cosine.js b/cosine.js
@@ -1,2 +1,2 @@
-import { sin, PI } from './_util.js'
+import { sin, PI } from './util.js'
 export default function cosine (i, N) { return sin(PI * i / (N - 1)) }
diff --git a/dolphChebyshev.js b/dolphChebyshev.js
@@ -1,4 +1,4 @@
-import { cos, abs, cosh, acosh, acos, pow, PI, PI2, normalize } from './_util.js'
+import { cos, abs, cosh, acosh, acos, pow, PI, PI2, normalize } from './util.js'
 export default function dolphChebyshev (i, N, attenuation) {
 	if (attenuation == null) attenuation = 100
 	let c = dolphChebyshev
diff --git a/dpss.js b/dpss.js
@@ -1,4 +1,4 @@
-import { sin, exp, sqrt, abs, PI, PI2, normalize } from './_util.js'
+import { sin, exp, sqrt, abs, PI, PI2, normalize } from './util.js'
 export default function dpss (i, N, W) {
 	if (W == null) W = 0.1
 	let c = dpss
diff --git a/exactBlackman.js b/exactBlackman.js
@@ -1,2 +1,2 @@
-import { cosineSum } from './_util.js'
+import { cosineSum } from './util.js'
 export default function exactBlackman (i, N) { return cosineSum(i, N, [0.42659, 0.49656, 0.076849]) }
diff --git a/exponential.js b/exponential.js
@@ -1,4 +1,4 @@
-import { abs, exp } from './_util.js'
+import { abs, exp } from './util.js'
 export default function exponential (i, N, tau) {
 	if (tau == null) tau = 1
 	return exp(-abs(2 * i - N + 1) / (tau * (N - 1)))
diff --git a/flatTop.js b/flatTop.js
@@ -1,2 +1,2 @@
-import { cosineSum } from './_util.js'
+import { cosineSum } from './util.js'
 export default function flatTop (i, N) { return cosineSum(i, N, [1, 1.93, 1.29, 0.388, 0.028]) }
diff --git a/gaussian.js b/gaussian.js
@@ -1,4 +1,4 @@
-import { exp } from './_util.js'
+import { exp } from './util.js'
 export default function gaussian (i, N, sigma) {
 	if (sigma == null) sigma = 0.4
 	let x = (2 * i - N + 1) / (sigma * (N - 1))
diff --git a/generalizedNormal.js b/generalizedNormal.js
@@ -1,4 +1,4 @@
-import { abs, exp, pow } from './_util.js'
+import { abs, exp, pow } from './util.js'
 export default function generalizedNormal (i, N, sigma, p) {
 	if (sigma == null) sigma = 0.4
 	if (p == null) p = 2
diff --git a/hamming.js b/hamming.js
@@ -1,2 +1,2 @@
-import { cos, PI2 } from './_util.js'
+import { cos, PI2 } from './util.js'
 export default function hamming (i, N) { return 0.54 - 0.46 * cos(PI2 * i / (N - 1)) }
diff --git a/hann.js b/hann.js
@@ -1,2 +1,2 @@
-import { cos, PI2 } from './_util.js'
+import { cos, PI2 } from './util.js'
 export default function hann (i, N) { return 0.5 - 0.5 * cos(PI2 * i / (N - 1)) }
diff --git a/hannPoisson.js b/hannPoisson.js
@@ -1,4 +1,4 @@
-import { cos, exp, abs, PI2 } from './_util.js'
+import { cos, exp, abs, PI2 } from './util.js'
 export default function hannPoisson (i, N, alpha) {
 	if (alpha == null) alpha = 2
 	return 0.5 * (1 - cos(PI2 * i / (N - 1))) * exp(-alpha * abs(2 * i - N + 1) / (N - 1))
diff --git a/kaiser.js b/kaiser.js
@@ -1,4 +1,4 @@
-import { sqrt, i0 } from './_util.js'
+import { sqrt, i0 } from './util.js'
 export default function kaiser (i, N, beta) {
 	if (beta == null) beta = 8.6
 	let x = (2 * i - N + 1) / (N - 1)
diff --git a/kaiserBesselDerived.js b/kaiserBesselDerived.js
@@ -1,4 +1,4 @@
-import { sqrt, abs, i0 } from './_util.js'
+import { sqrt, abs, i0 } from './util.js'
 export default function kaiserBesselDerived (i, N, beta) {
 	if (beta == null) beta = 8.6
 	let c = kaiserBesselDerived
diff --git a/lanczos.js b/lanczos.js
@@ -1,4 +1,4 @@
-import { sin, PI } from './_util.js'
+import { sin, PI } from './util.js'
 export default function lanczos (i, N) {
 	let x = 2 * i / (N - 1) - 1
 	return x === 0 ? 1 : sin(PI * x) / (PI * x)
diff --git a/nuttall.js b/nuttall.js
@@ -1,2 +1,2 @@
-import { cosineSum } from './_util.js'
+import { cosineSum } from './util.js'
 export default function nuttall (i, N) { return cosineSum(i, N, [0.355768, 0.487396, 0.144232, 0.012604]) }
diff --git a/planckTaper.js b/planckTaper.js
@@ -1,4 +1,4 @@
-import { exp } from './_util.js'
+import { exp } from './util.js'
 export default function planckTaper (i, N, epsilon) {
 	if (epsilon == null) epsilon = 0.1
 	let eN = epsilon * (N - 1)
diff --git a/powerOfSine.js b/powerOfSine.js
@@ -1,4 +1,4 @@
-import { sin, PI, pow } from './_util.js'
+import { sin, PI, pow } from './util.js'
 export default function powerOfSine (i, N, alpha) {
 	if (alpha == null) alpha = 2
 	return pow(sin(PI * i / (N - 1)), alpha)
diff --git a/rifeVincent.js b/rifeVincent.js
@@ -1,4 +1,4 @@
-import { cos, PI2 } from './_util.js'
+import { cos, PI2 } from './util.js'
 export default function rifeVincent (i, N, order) {
 	if (order == null) order = 1
 	let a
diff --git a/taylor.js b/taylor.js
@@ -1,4 +1,4 @@
-import { cos, acosh, pow, PI, PI2, normalize } from './_util.js'
+import { cos, acosh, pow, PI, PI2, normalize } from './util.js'
 export default function taylor (i, N, nbar, sll) {
 	if (nbar == null) nbar = 4
 	if (sll == null) sll = 30
diff --git a/tukey.js b/tukey.js
@@ -1,4 +1,4 @@
-import { cos, PI } from './_util.js'
+import { cos, PI } from './util.js'
 export default function tukey (i, N, alpha) {
 	if (alpha == null) alpha = 0.5
 	let half = 0.5 * alpha * (N - 1)
diff --git a/ultraspherical.js b/ultraspherical.js
@@ -1,4 +1,4 @@
-import { cos, PI, PI2, gegen, normalize } from './_util.js'
+import { cos, PI, PI2, gegen, normalize } from './util.js'
 export default function ultraspherical (i, N, mu, xmu) {
 	if (mu == null) mu = 1
 	if (xmu == null) xmu = 1
diff --git a/util.js b/util.js
@@ -1,4 +1,41 @@
-import { cos, sin, sqrt, abs, PI } from './_util.js'
+// ── Math shorthand ──
+
+export let { cos, sin, abs, exp, sqrt, PI, cosh, acosh, acos, pow, log10 } = Math
+export let PI2 = 2 * PI
+
+// ── Internal helpers (used by window functions) ──
+
+export function cosineSum (i, N, a) {
+	let f = PI2 * i / (N - 1), v = a[0]
+	for (let k = 1; k < a.length; k++) v += (k % 2 ? -1 : 1) * a[k] * cos(k * f)
+	return v
+}
+
+export function i0 (x) {
+	let s = 1, t = 1
+	for (let k = 1; k <= 25; k++) { t *= (x / (2 * k)) * (x / (2 * k)); s += t; if (t < 1e-15 * s) break }
+	return s
+}
+
+export function gegen (n, mu, x) {
+	if (n === 0) return 1
+	if (n === 1) return 2 * mu * x
+	let c0 = 1, c1 = 2 * mu * x
+	for (let k = 2; k <= n; k++) {
+		let c2 = (2 * x * (k + mu - 1) * c1 - (k + 2 * mu - 2) * c0) / k
+		c0 = c1; c1 = c2
+	}
+	return c1
+}
+
+export function normalize (w) {
+	let peak = 0
+	for (let i = 0; i < w.length; i++) if (abs(w[i]) > peak) peak = abs(w[i])
+	if (peak > 0) for (let i = 0; i < w.length; i++) w[i] /= peak
+	return w
+}
+
+// ── Public utilities ──
 
 /** Generate a full window as Float64Array. */
 export function generate (fn, N, ...params) {
@@ -24,7 +61,7 @@ export function enbw (fn, N, ...params) {
 export function scallopLoss (fn, N, ...params) {
 	let s = 0, re = 0, im = 0
 	for (let i = 0; i < N; i++) { let v = fn(i, N, ...params); s += v; re += v * cos(PI * i / N); im -= v * sin(PI * i / N) }
-	return s === 0 ? Infinity : -20 * Math.log10(sqrt(re * re + im * im) / abs(s))
+	return s === 0 ? Infinity : -20 * log10(sqrt(re * re + im * im) / abs(s))
 }
 
 /** COLA deviation. Returns max relative deviation from constant overlap-add sum; 0 = perfect. */

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-import { abs, cos, PI2 } from './_util.js'`
	`1`	`+import { abs, cos, PI2 } from './util.js'`
`2`	`2`	`export default function bartlettHann (i, N) {`
`3`	`3`	`let x = i / (N - 1)`
`4`	`4`	`return 0.62 - 0.48 * abs(x - 0.5) - 0.38 * cos(PI2 * x)`
Original file line number	Diff line number	Diff line change
`@@ -1,2 +1,2 @@`
`1`		`-import { cosineSum } from './_util.js'`
	`1`	`+import { cosineSum } from './util.js'`
`2`	`2`	`export default function blackman (i, N) { return cosineSum(i, N, [0.42, 0.5, 0.08]) }`
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-import { abs, cos, sin, PI } from './_util.js'`
	`1`	`+import { abs, cos, sin, PI } from './util.js'`
`2`	`2`	`export default function bohman (i, N) {`
`3`	`3`	`let a = abs((2 * i - N + 1) / (N - 1))`
`4`	`4`	`if (a >= 1) return 0`
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-import { exp } from './_util.js'`
	`1`	`+import { exp } from './util.js'`
`2`	`2`	`export default function confinedGaussian (i, N, sigmaT) {`
`3`	`3`	`if (sigmaT == null) sigmaT = 0.1`
`4`	`4`	`let L = N + 1, half = (N - 1) / 2`
Original file line number	Diff line number	Diff line change
`@@ -1,2 +1,2 @@`
`1`		`-import { sin, PI } from './_util.js'`
	`1`	`+import { sin, PI } from './util.js'`
`2`	`2`	`export default function cosine (i, N) { return sin(PI * i / (N - 1)) }`
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-import { cos, abs, cosh, acosh, acos, pow, PI, PI2, normalize } from './_util.js'`
	`1`	`+import { cos, abs, cosh, acosh, acos, pow, PI, PI2, normalize } from './util.js'`
`2`	`2`	`export default function dolphChebyshev (i, N, attenuation) {`
`3`	`3`	`if (attenuation == null) attenuation = 100`
`4`	`4`	`let c = dolphChebyshev`
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-import { sin, exp, sqrt, abs, PI, PI2, normalize } from './_util.js'`
	`1`	`+import { sin, exp, sqrt, abs, PI, PI2, normalize } from './util.js'`
`2`	`2`	`export default function dpss (i, N, W) {`
`3`	`3`	`if (W == null) W = 0.1`
`4`	`4`	`let c = dpss`