matlab taylorwin(n,nbar,sll)加窗函数 c/c++实现代码

以下是MATLAB和C/C++语言的taylorwin(n,nbar,sll)加窗函数的实现代码。

MATLAB代码：

function w = taylorwin(n, nbar, sll)
% TAYLORWIN Returns a Taylor window of length n, with nbar sidelobe
% attenuation (in dB) and sll minimum stopband attenuation (in dB).
% The window is normalized to have a peak value of 1.
%
% Usage: w = taylorwin(n, nbar, sll)
%
% Arguments:
% n    - the length of the window
% nbar - the desired sidelobe attenuation (in dB)
% sll  - the minimum desired stopband attenuation (in dB)
%
% Returns:
% w    - the Taylor window vector of length n
%
% Reference:
% Harris, F. J. (1978). On the use of windows for harmonic analysis with
% the discrete Fourier transform. Proceedings of the IEEE, 66(1), 51-83.

if n < 2
    error('Window length must be greater than 1')
end

if nbar < 0
    error('Sidelobe attenuation must be non-negative')
end

if sll < 0
    error('Minimum stopband attenuation must be non-negative')
end

alpha = (n-1)/2;
w = zeros(n,1);

% Compute the weighting factor k
k = -20*log10(sqrt(10^(-nbar/10) - 10^(-sll/10))) / alpha;

% Compute the Taylor coefficients
tay = zeros(1,n);
tay(1) = 1;
for i = 2:n
    tay(i) = tay(i-1) * (k^2 - ((i-1)/alpha)^2);
end

% Compute the window
for i = 1:n
    w(i) = tay(i) / tay(1);
end

% Normalize the window to have a peak value of 1
w = w / max(w);

C/C++代码：

#include <math.h>

void taylorwin(int n, int nbar, int sll, double *w)
{
    int i;
    double alpha = (n-1) / 2.0;
    double k;
    double tay[n];
    double maxval = 0.0;

    if (n < 2) {
        return;
    }

    if (nbar < 0) {
        return;
    }

    if (sll < 0) {
        return;
    }

    // Compute the weighting factor k
    k = -20*log10(sqrt(pow(10,-nbar/10) - pow(10,-sll/10))) / alpha;

    // Compute the Taylor coefficients
    tay[0] = 1;
    for (i=1; i<n; i++) {
        tay[i] = tay[i-1] * (pow(k,2) - pow((i-1)/alpha,2));
    }

    // Compute the window
    for (i=0; i<n; i++) {
        w[i] = tay[i] / tay[0];
        if (w[i] > maxval) {
            maxval = w[i];
        }
    }

    // Normalize the window to have a peak value of 1
    for (i=0; i<n; i++) {
        w[i] = w[i] / maxval;
    }
}