%
%  half_cosine_fade.m  ver 1.0  July 12, 2012
%
%  by Tom Irvine
%
function[y]=half_cosine_fade(y)
%
disp(' ');
disp(' Enter percent fade (example: 1 for 1%)  ');
fper=input(' ');
fper=fper/100;
%
n=length(y);
%
na=round(fper*n);
nb=n-na;
delta=n-nb;
%
for(i=1:na)
    arg=pi*(( (i-1)/(na-1) )+1); 
    y(i)=y(i)*0.5*(1+(cos(arg)));
end
%
for(i=nb:n)
    arg=pi*( (i-nb)/delta );
    y(i)=y(i)*(1+cos(arg))*0.5;
end