MATLAB: Get the reflection of function

functionreflection

how can i get the reflection f(-t) of f(t) ?

t = linspace(0,2*pi) ;
f = @(t) sin(t) ;
figure
hold on
% f(t)
y1 = plot(t,f(t),'r') ;
%f(-t) 
y2 = plot(t,f(-t),'b') ;
legend('f(t)','f(-t)')

Maybe try the following:

n=[1 2 3 4 5 6]; 
ki=2.*pi.*n
k=1.2
kz=sqrt((ki.^2-k.^2))
for i= 1:length(kz)-1
RTE(i)=(kz(i)-kz(i+1))/(kz(i)+kz(i+1));
end
RTE

If anyone needs to know the answer to this. It is because he is not doing element wise division

R=((n_S-1).^2)/((n_S+1).^2);

should be

R=((n_S-1).^2)./((n_S+1).^2);

Note the './' instead of '/' for division