% myfft.m
N=128;
n=[0:1:127];
load sam s;
fs=50*32;
w=0.54-0.46*cos(2*pi*n/N);
r=s.*w;
v=fft(r,128);
vz=abs(v)/64*1.852;
stem(abs(v)/64*1.852);
u=abs(v);
A=zeros(1,7);
for I=0:6
    y1=u(5+4*I);
    y2=u(6+4*I);
    y3=u(4+4*I);
    max=y2;
    if y3>y2
        max=y3;
    end
    if max==y3
        t=y1;
        y1=max;
        y2=t;
    end
    b=(y2-y1)/(y2+y1);
    a=1.21874943*b+0.13349531*b^3+0.05301420*b^5+0.03656*b^7;
    A(I+1)=(y1+y2)*(2.26557103+1.22719978*a^2+0.3761*a^4+0.09767389*a^6)/128;
end