gibbs.m

Gibbs现象,画出由N次谐波合成的周期方波的波形图

clear all
x1=linspace(-pi,pi,5000);
for i=1:1;
    subplot(1,1,i);
    y1=1/2;                       %画波形！
    if i==0;
        y1=y1+2/pi*cos(x1);
    else  for j=1:2:(30*i);
            y1=y1+((-1)^((j-1)/2)*2)/(j*pi)*cos(j*x1);
            
          end   
    end      
    plot(x1,y1,'b-')
    grid on
    hold on
    
    x2=[-pi,-pi/2,pi/2,pi];    %画方波！
    y2=[0,1,0,0];
    stairs(x2,y2,'r:');
    title('Gibbs现象');
    x=2.1;
    y=0.9;
    s='N=30';
    text(x,y,s)
end