% clc;clear all;close all;t=0:0.001:5;y=20*sin(2*pi*10.*t);figure(1)plot(t,y,r);grid on% % Fs=1000; % Nfft=length(y); % range=onesided; window=hamming(length(y); % noverlap=0; % Px,f=pwelch(y,window,noverlap,Nfft,Fs,range); % FFTfigure(2)plot(f,Px,r);grid onset(gca,Xscale,log,Yscale,log);acc_x=f;acc_y=Px;ww=zeros;acc_num=0;for i=1:length(acc_x) % if acc_x(i)=0.5 & acc_x(i)=2 & acc_x(i)=4 & acc_x(i)=12.5 & acc_x(i)80 ww(i)=12.5/acc_x(i); else ww(i)=0; end acc_num=acc_num+ww(i)2*acc_y(i)*(acc_x(2)-acc_x(1); % endacc_Q=(acc_num)0.5; %