function c=myifft(f)
% primitive inverse fft implementation for powers of two
n=length(f);
if n==1
    c=f;
    return
end
m=n/2;
fplus=f(1:m)+f(m+1:n);
fminus=exp(+2*pi*(0:m-1)'/n).*(f(1:m)-f(m+1:n));
ceven=myifft(fplus);
codd =myifft(fminus);
c(1+2*(0:m-1),1)=ceven;
c(2+2*(0:m-1),1)=codd;
return
