import type { FnN2 } from "@thi.ng/api" ; import { HALF_PI } from "@thi.ng/math/api" ; /**
 * Reference:
 * -  https * -  http *
 * Interactive graph:
 *  https param n param i export const gibbs = ( n , i ) => Math . cos ( ( ( i - 1 ) * HALF_PI ) / n ) ** 2 ; remarks Used for attenuating the  gibbs factor when summing a Fourier
 * series. Linearly attentuates higher harmonics, with the first bin
 * receiving a weight on 1 and the last bin `1/n`.
 *
 *  param k param n export const fejer = ( k , n ) => ( n - k ) / n ; /**
 * Polynomial attenuation to create bandlimited version of a signal.
 *
 * -  http * -  http param dt param t export const polyBLEP = ( dt , t ) => t < dt ? ( ( t /= dt ) , t + t - t * t - 1 ) : t > 1 - dt ? ( ( t = ( t - 1 ) / dt ) , t * t + t + t + 1 ) : 0 ;