pkg load signal
graphics_toolkit gnuplot
clear all; close all; clc

 M=5600;        % big number, divisible by 7 and 8
% Generate M+1 samples of a Triangle window
 window = triang(M+1);
 N=8;           % actual window size, in "hops"

% Sample the window.
% Scale the abscissa. 0:M samples --> 0:7 "hops", and take 8 symmetrical hops, from 0 to 7
 sam_per_hop_7 = M/7;
 symmetric = window(1+(0:7)*sam_per_hop_7);

% Scale the abscissa. 0:M samples --> 0:8 "hops", and take 8 asymmetrical hops, from 0 to 7
 sam_per_hop_8 = M/8;
 periodic = window(1+(0:7)*sam_per_hop_8);

% Compare equivalent noise bandwidths (info only)
ENBW_symmetric = N*sum(symmetric.^2)/sum(symmetric)^2
ENBW_periodic  = N*sum(periodic.^2) /sum(periodic)^2
 
hfig = figure
plot(0:7, symmetric, 'color', 'red', '.')   % plot the symmetric coefficients
hold on                                     % same axes for next 3 plots
 
plot(0:7, periodic,  'color', 'blue', '.')  % plot the periodic  coefficients

% Connect the dots
hops = (0:M)/sam_per_hop_8;
plot(hops, window, 'color', 'blue')            % periodic

hops = (0:M)/sam_per_hop_7;
plot(hops, window, 'color', 'red')             % symmetric
 
xlim([0 8])
set(gca,'FontSize',14)
set(gca, "yaxislocation", "origin")
set(gca, 'xgrid', 'on');
set(gca, 'ygrid', 'on');
set(gca, 'ytick', [0:.25:1]);
set(gca, 'xtick', [0:8]);
text(3.3, 0.27, 'Matlab "symmetric" \rightarrow', 'color', 'red', 'FontSize',12)

str = {'\leftarrow Matlab "periodic"','     ("DFT-even")'};
text(5.2, 0.74, str, 'color', 'blue', 'FontSize',12)

title('Two 8-point Bartlett window functions','FontSize', 14);
xlabel('\leftarrow  n  \rightarrow')

% Or use the export function on the GNUPlot figure toolbar.
print(hfig,"-dsvg", "-S574,390","-color", 'C:\Users\BobK\8-point windows.svg')