There is a small error in your script. Here is the corrected one:
hR1 = resistor(50,'R50');
hckt1 = circuit('example2');
add(hckt1,[1 2],hR1)
add(hckt1,[2 3],resistor(100))
setports (hckt1, [1 0],[3 0])
freq = linspace (1e3,2e3,100);
S = sparameters(hckt1,freq,100);
for cont = 1:numel(freq) % Iterate for the length of freq
S.Parameters(:,:,cont) = 5*S.Parameters(:,:,cont) - 10;
end
