zhe13.m

用MATLAB做得fft谱分析

function y=Apcm(x)
x=x/max(x);
z=sign(x);
x=abs(x);
for i=1:length(x);
     if((x(i)>=0)&(x(i)<1/64))
        y(i)=16*x(i);
    else if(x(i)>=1/64&x(i)<1/32)
            y(i)=8*x(i)+1/8;
            else if(x(i)>=1/32&x(i)<1/16)   
            y(i)=4*x(i)+2/8;
                else if(x(i)>=1/16&x(i)<1/8)
                       y(i)=2*x(i)+3/8; 
                       else if(x(i)>=1/8&x(i)<1/4)
                       y(i)=1*x(i)+4/8;
                       else if(x(i)>=1/4&x(i)<1/2)
                       y(i)=1/2*x(i)+5/8;
                       else if(x(i)>=1/2&x(i)<=1)
                       y(i)=1/4*x(i)+6/8;
                           end;end;end;end;end;end;end;end;
y=z.*y;