clear

clc

close all

fs=20;

width=16;

height=16;

t=(1/fs:1/fs:200)';

signal=sin(2*pi*0.1)+rand(length(t),1)+3/100*t;

figure(1)

set(gcf,'units','centimeters','Position',[1,2+height,width,height])

plot(t,signal)

smoothed_avg_values = smooth(signal, 20); % 这里的10是平滑窗口的长度

figure(2)

set(gcf,'units','centimeters','Position',[1+width,2+height,width,height])

plot(t,signal)

hold on

plot(t,smoothed_avg_values)

hold off

overlap=5; %每次往前推进的数值。

window_length=200; %保证其是个偶数

num_windows = floor((length(signal) - window_length) / overlap) ;

rms_values = zeros(num_windows, 1);

for II=1:num_windows

start_idx=(II - 1) * overlap + 1;

end_idx=start_idx+ window_length;

rms_values(II,1)=rms(signal(start_idx:end_idx));

rms_time(II,1)=start_idx+window_length/2;

end

figure(3)

set(gcf,'units','centimeters','Position',[1+2*width,2+height,width,height])

plot(rms_time/fs,rms_values)

figure(4)

set(gcf,'Units','centimeters','Position',[1+3*width,2+height,width,height])

plot(t,signal,'b')

hold on

plot(t,smoothed_avg_values,'r')

plot(rms_time/fs,rms_values,'m','LineWidth',2)

hold off